v3.26.3
Business Segments (Summary Of Company's Segment Results) (Detail) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Segment Reporting [Line Items]          
Revenues $ 27 [1] $ 25 [2] $ 75 [3] $ 72 [4]  
Net gains (losses) on financial instruments at fair value and foreign exchange (8) (12) 5 (29)  
Revenues of consolidated VIEs 7 2 7 9  
Inter-segment revenues 0 [5] 0 [6] 0 [7] 0 [8]  
Total revenues 26 [9] 15 [10] 77 [11] 52 [12]  
Losses and loss adjustment (12) (50) (6) (34)  
Compensation and benefits 8 13 34 34  
Interest 46 50 141 148  
Inter-segment service charge 0 0 0 0  
Other segment items 7 [13] 9 [14] 15 [15] 29 [16]  
Total expenses 49 22 184 177  
Income (loss) from continuing operations before income taxes (23) (7) (107) (125)  
Total assets per reportable segment 1,830 2,050 1,830 2,050  
Assets held for sale   10   10  
Total assets 1,830 2,060 1,830 2,060 $ 2,013
Operating Segments [Member] | US Public Finance Insurance [Member]          
Segment Reporting [Line Items]          
Revenues 17 [1] 15 [2] 48 [3] 41 [4]  
Net gains (losses) on financial instruments at fair value and foreign exchange (3) 1 (4) 2  
Revenues of consolidated VIEs 0 0 0 0  
Inter-segment revenues 6 [5] 5 [6] 17 [7] 18 [8]  
Total revenues 20 [9] 21 [10] 61 [11] 61 [12]  
Losses and loss adjustment 3 (54) 10 (45)  
Compensation and benefits 0 0 0 0  
Interest 0 0 0 0  
Inter-segment service charge 6 7 22 24  
Other segment items 3 [13] 3 [14] 9 [15] 10 [16]  
Total expenses 12 (44) 41 (11)  
Income (loss) from continuing operations before income taxes 8 65 20 72  
Total assets per reportable segment 1,415 1,524 1,415 1,524  
Operating Segments [Member] | Corporate Operations [Member]          
Segment Reporting [Line Items]          
Revenues 6 [1] 6 [2] 16 [3] 17 [4]  
Net gains (losses) on financial instruments at fair value and foreign exchange 2 5 10 (3)  
Revenues of consolidated VIEs 0 0 0 0  
Inter-segment revenues 10 [5] 11 [6] 33 [7] 38 [8]  
Total revenues 18 [9] 22 [10] 59 [11] 52 [12]  
Losses and loss adjustment 0 0 0 0  
Compensation and benefits 8 13 34 34  
Interest 16 17 49 53  
Inter-segment service charge 0 0 0 0  
Other segment items 4 [13] 5 [14] 10 [15] 13 [16]  
Total expenses 28 35 93 100  
Income (loss) from continuing operations before income taxes (10) (13) (34) (48)  
Total assets per reportable segment 577 650 577 650  
Operating Segments [Member] | International And Structured Finance Insurance [Member]          
Segment Reporting [Line Items]          
Revenues 4 [1] 4 [2] 11 [3] 14 [4]  
Net gains (losses) on financial instruments at fair value and foreign exchange (7) (18) (11) (28)  
Revenues of consolidated VIEs 7 2 7 9  
Inter-segment revenues 2 [5] 2 [6] 6 [7] 5 [8]  
Total revenues 6 [9] (10) [10] 13 [11] 0 [12]  
Losses and loss adjustment (15) 4 (16) 11  
Compensation and benefits 0 0 0 0  
Interest 36 38 109 112  
Inter-segment service charge 4 4 10 11  
Other segment items 2 [13] 4 [14] 3 [15] 15 [16]  
Total expenses 27 50 106 149  
Income (loss) from continuing operations before income taxes (21) (60) (93) (149)  
Total assets per reportable segment 629 670 629 670  
Intersegment Elimination [Member]          
Segment Reporting [Line Items]          
Revenues 0 [1] 0 [2] 0 [3] 0 [4]  
Net gains (losses) on financial instruments at fair value and foreign exchange 0 0 0 0  
Revenues of consolidated VIEs 0 0 0 0  
Inter-segment revenues (18) [5] (18) [6] (56) [7] (61) [8]  
Total revenues (18) [9] (18) [10] (56) [11] (61) [12]  
Losses and loss adjustment 0 0 0 0  
Compensation and benefits 0 0 0 0  
Interest (6) (5) (17) (17)  
Inter-segment service charge (10) (11) (32) (35)  
Other segment items (2) [13] (3) [14] (7) [15] (9) [16]  
Total expenses (18) (19) (56) (61)  
Income (loss) from continuing operations before income taxes 0 1 0 (0)  
Total assets per reportable segment $ (791) [17] $ (794) [18] $ (791) [17] $ (794) [18]  
[1] Consists primarily of net premiums earned, net investment income, net realized investment gains (losses), fees and reimbursements and other net realized gains (losses).
[2] Consists primarily of net premiums earned, net investment income, net realized investment gains (losses), fees and reimbursements and other net realized gains (losses).
[3] Consists primarily of net premiums earned, net investment income, net realized investment gains (losses), fees and reimbursements and other net realized gains (losses).
[4] Consists primarily of net premiums earned, net investment income, net realized investment gains (losses), fees and reimbursements and other net realized gains (losses).
[5] Primarily represents intercompany service charges and intercompany net investment income.
[6] Primarily represents intercompany service charges and intercompany net investment income.
[7] Primarily represents intercompany service charges and intercompany net investment income.
[8] Primarily represents intercompany service charges and intercompany net investment income.
[9] Includes net investment income of $15 million, $6 million, $2 million, and ($6) million for the U.S. Public Finance, Corporate, International and Structured Finance, and Eliminations segments, respectively.
[10] Includes net investment income of $14 million, $6 million, $2 million, and ($5) million for the U.S. Public Finance, Corporate, International and Structured Finance, and Eliminations segments, respectively.
[11] Includes net investment income of $45 million, $17 million, $8 million, and ($18) million for the U.S. Public Finance, Corporate, International and Structured Finance, and Eliminations segments, respectively.
[12] Includes net investment income of $44 million, $19 million, $8 million, and ($17) million for the U.S. Public Finance, Corporate, International and Structured Finance, and Eliminations segments, respectively.
[13] Other segment items for each reportable segment include:

a. U.S. Public Finance Insurance - amortization of deferred acquisition costs ("DAC"), professional service fees, occupancy costs and other operating expenses;

b. Corporate - professional service fees, occupancy costs and other operating expenses;

c. International and Structured Finance Insurance - expenses of consolidated VIEs, amortization of DAC, professional service fees and other operating expenses, and

d. Elimination - inter-segment amortization of DAC and inter-segment occupancy costs.
[14] Other segment items for each reportable segment include:

a. U.S. Public Finance Insurance - amortization of DAC, professional service fees, occupancy costs and other operating expenses;

b. Corporate - professional service fees, occupancy costs and other operating expenses;

c. International and Structured Finance Insurance - expenses of consolidated VIEs, amortization of DAC, professional service fees and other operating expenses, and

d. Elimination - inter-segment amortization of DAC and inter-segment occupancy costs.
[15] Other segment items for each reportable segment include:

a. U.S. Public Finance Insurance - amortization of DAC, professional service fees, occupancy costs and other operating expenses;

b. Corporate - professional service fees, occupancy costs and other operating expenses;

c. International and Structured Finance Insurance - expenses of consolidated VIEs, amortization of DAC, professional service fees and other operating expenses, and

d. Elimination - inter-segment amortization of DAC and inter-segment occupancy costs.
[16] Other segment items for each reportable segment include:

a. U.S. Public Finance Insurance - amortization of DAC, professional service fees, occupancy costs and other operating expenses;

b. Corporate - professional service fees, occupancy costs and other operating expenses;

c. International and Structured Finance Insurance - expenses of consolidated VIEs, amortization of DAC, professional service fees and other operating expenses, and

d. Elimination - inter-segment amortization of DAC and inter-segment occupancy costs.
[17] Consists principally of intercompany reinsurance balances.
[18] Consists principally of intercompany reinsurance balances.