Stock-Based Compensation - Summary of Deferred Stock Awards to Non-Employee Directors (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Deferred awards outstanding, beginning of year (in shares)	65,679	65,679	132,699
Shares diversified (in shares)	0	0	0
Shares issued upon retirement (in shares)	(1,857)		(67,020)
Deferred awards outstanding, end of year (in shares)	63,822	65,679	65,679
Diversified Deferred Stock Award
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Deferred awards outstanding, beginning of year (in shares)	6,998	5,598	12,250
Shares diversified (in shares)	0	1,400	13,348
Shares issued upon retirement (in shares)	0		(20,000)
Deferred awards outstanding, end of year (in shares)	6,998	6,998	5,598
Undiversified Deferred Stock Award
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Deferred awards outstanding, beginning of year (in shares)	58,681	60,081	120,449
Shares diversified (in shares)	0	(1,400)	(13,348)
Shares issued upon retirement (in shares)	(1,857)		(47,020)
Deferred awards outstanding, end of year (in shares)	56,824	58,681	60,081