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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Shareholders' Equity - Comprehensive Capital Plan (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Repurchase of common shares			$ 820,000,000	$ 466,000,000
Cash dividends declared on common shares (in usd per share)	$ 0.17	$ 0.095	$ 0.395	$ 0.275
2018 Capital Plan [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Authorized amount of share repurchases	$ 1,225,000,000		$ 1,225,000,000
Common shares repurchased, value	542,000,000
Repurchase of common shares	541,000,000
Employee equity compensation program Common Share repurchases	$ 1,000,000
Cash dividends declared on common shares (in usd per share)	$ 0.17