Shareholders' Equity - Common Stock and Debt Repurchase Authorizations (Details) - USD ($) shares in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021	Jul. 28, 2021	Nov. 07, 2019	Nov. 02, 2018
Class of Stock [Line Items]
Dividends declared or paid	$ 0	$ 0
Repurchase Program, November 2018
Class of Stock [Line Items]
Remaining authorized repurchase amount under debt repurchase	76,000,000		$ 76,000,000
Repurchase Program, November 2018 | Debt Securities
Class of Stock [Line Items]
Debt repurchase program, amount authorized						$ 100,000,000
Common Stock | Repurchase Program, July 2021
Class of Stock [Line Items]
Authorized repurchase of securities, with debt reduction target (up to)				$ 250,000,000
Remaining authorized repurchase amount under the stock repurchase program	$ 250,000,000		250,000,000
Common Stock | Repurchase Progam, November 2019
Class of Stock [Line Items]
Authorized repurchase of securities, with debt reduction target (up to)					$ 325,000,000
Common Stock | Repurchase Program, July And November 2019
Class of Stock [Line Items]
Remaining authorized repurchase amount under the stock repurchase program			$ 0
Number of shares authorized to be repurchased (in shares)			2.5
Shares repurchased during period			$ 59,000,000