Shareholders' Equity and Loss Per Common Share - Common Shares Repurchased (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended	76 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Feb. 28, 2025
Shareholders' Equity and Loss Per Common Share
Authorized value of shares for repurchase						$ 2,000.0
Repurchase and retired common shares	208,565	11,200,000	1,800,000	23,300,000	85,500,000
Repurchase and retired common shares, Value	$ 3.0	$ 184.9	$ 28.4	$ 372.4	$ 1,600.0
Average purchase price	$ 14.37	$ 16.54	$ 15.35	$ 15.96	$ 18.72

Number of shares that have been repurchased and retired during the period.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details