Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions		Total	CECL ASU Adjustment to RE	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) CECL ASU Adjustment to RE
Beginning balance (in shares) at Dec. 31, 2018				57,749,464
Beginning balance at Dec. 31, 2018		$ 1,570		$ 1	$ 1,522	$ (47)	$ 94
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		218					218
Total other comprehensive income		48				48
Shares issued from the Employee Stock Purchase Plan (in shares)				106,881
Shares issued from the Employee Stock Purchase Plan		0
Dividends declared and paid (in shares)				376
Dividends declared and paid		(9)					(9)
Stock-based compensation (in shares)				292,220
Stock-based compensation		11			11
Repurchase of common shares (in shares)	[1]			(1,517,705)
Repurchase of common shares	[1]	(50)			(50)
Ending balance (in shares) at Dec. 31, 2019				56,631,236
Ending balance at Dec. 31, 2019		$ 1,788	$ (23)	$ 1	1,483	1	303	$ (23)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]		Accounting Standards Update 2016-13 [Member]	Accounting Standards Update 2016-13 [Member]
Net income		$ 538					538
Total other comprehensive income		46				46
Shares issued from the Employee Stock Purchase Plan (in shares)				181,875
Dividends declared and paid (in shares)				729
Dividends declared and paid		(11)					(11)
Stock-based compensation (in shares)				429,874
Stock-based compensation		13			13
Repurchase of common shares (in shares)	[1]			(4,587,647)
Repurchase of common shares	[1]	(150)			(150)
Ending balance (in shares) at Dec. 31, 2020				52,656,067
Ending balance at Dec. 31, 2020		2,201		$ 1	1,346	47	807
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		533					533
Total other comprehensive income		(12)				(12)
Shares issued from the Employee Stock Purchase Plan (in shares)				106,707
Shares issued from the Employee Stock Purchase Plan		0
Dividends declared and paid (in shares)				485
Dividends declared and paid		(13)					(13)
Stock-based compensation (in shares)				434,391
Stock-based compensation		9			9
Ending balance (in shares) at Dec. 31, 2021				53,197,650
Ending balance at Dec. 31, 2021		$ 2,718		$ 1	$ 1,355	$ 35	$ 1,327

[1] Includes dividend reinvestment shares.