DEBT AND EQUITY SECURITIES - Schedule of Fair Values of Trading Securities (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	$ 931	$ 1,146
Level One—Quoted Prices in Active Markets for Identical Assets \| Interest-bearing money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	183	441
Level One—Quoted Prices in Active Markets for Identical Assets \| Exchange-traded funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	8	7
Level One—Quoted Prices in Active Markets for Identical Assets \| Common shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	13	13
Level One—Quoted Prices in Active Markets for Identical Assets \| Marketable securities held to fund rabbi trusts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	648	594
Level Two—Significant Other Observable Inputs \| U.S. government obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	59	68
Level Two—Significant Other Observable Inputs \| U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	6	9
Level Two—Significant Other Observable Inputs \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	6	7
Level Two—Significant Other Observable Inputs \| Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	5	4
Level Two—Significant Other Observable Inputs \| Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	2	1
Level Two—Significant Other Observable Inputs \| Municipal and provincial notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	$ 1	$ 2