Earnings per Common Share (Schedule of Basic and Diluted Earnings per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2022		Jun. 30, 2021	Jun. 30, 2022		Jun. 30, 2021
Class of Stock [Line Items]
Net income from continuing operations		$ 482	[1]	$ 899	$ 1,137	[1]	$ 1,695	[1]
Net income from continuing operations attributable to common stockholders	[1]	454		899	1,081		1,695
Income from discontinued operations, net of tax	[1]	0		1	0		1
Net income attributable to common stockholders	[1]	$ 454		$ 900	$ 1,081		$ 1,696
Basic weighted-average common shares outstanding	[1],[2]	322,057		370,412	328,830		372,807
Diluted weighted-average common shares outstanding	[1],[2]	324,027		373,029	330,882		375,265
Basic earnings per common share
Net income from continuing operations (in dollars per share)	[1]	$ 1.41		$ 2.43	$ 3.29		$ 4.55
Net income (in dollars per share)	[1]	1.41		2.43	3.29		4.55
Diluted earnings per common share
Net income from continuing operations (in dollars per share)	[1]	1.40		2.41	3.27		4.52
Net income (in dollars per share)	[1]	$ 1.40		$ 2.41	$ 3.27		$ 4.52
Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends	[1]	$ (16)		$ 0	$ (32)		$ 0
Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends	[1]	$ (12)		$ 0	$ (24)		$ 0

[1] Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated based on unrounded numbers.

[2] Includes shares related to share-based compensation that vested but were not yet issued.