Shareholders' Equity - Comprehensive Capital Plan (Details) - USD ($)	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Repurchase of common shares	$ 117,000,000	$ 167,000,000
Cash dividends declared on common shares (in usd per share)	$ 0.185	$ 0.17
2019 Capital Plan [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Authorized amount of share repurchases	$ 1,000,000,000.0
Common shares repurchased, value	152,000,000
Repurchase of common shares	117,000,000
Employee equity compensation program Common Share repurchases (less than)	$ 1,000,000
Cash dividends declared on common shares (in usd per share)	$ 0.185

Aggregate dividends declared during the period for each share of common stock outstanding.

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The cash outflow to reacquire common stock during the period.

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