Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Income	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment
Beginning balance (in shares) at Dec. 31, 2019			56,631,236
Beginning balance at Dec. 31, 2019	$ 1,788	$ (23)	$ 1	$ 1,483	$ 1	$ 303	$ (23)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	46					46
Total other comprehensive income	30				30
Shares issued from Employee Stock Purchase Plan (in shares)			59,252
Stock-based compensation (in shares)			39,081
Stock-based compensation	4			4
Dividends declared and paid (in shares)			220
Dividends declared and paid	(3)					(3)
Ending balance (in shares) at Mar. 31, 2020			56,729,789
Ending balance at Mar. 31, 2020	$ 1,842		$ 1	1,487	31	323
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Beginning balance (in shares) at Dec. 31, 2019			56,631,236
Beginning balance at Dec. 31, 2019	$ 1,788	$ (23)	$ 1	1,483	1	303	$ (23)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	161
Total other comprehensive income	45
Ending balance (in shares) at Jun. 30, 2020			56,943,979
Ending balance at Jun. 30, 2020	1,971		$ 1	1,488	46	436
Beginning balance (in shares) at Mar. 31, 2020			56,729,789
Beginning balance at Mar. 31, 2020	1,842		$ 1	1,487	31	323
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	116					116
Total other comprehensive income	15				15
Shares issued from Employee Stock Purchase Plan (in shares)			46,591
Stock-based compensation (in shares)			167,410
Stock-based compensation	1			1
Dividends declared and paid (in shares)			189
Dividends declared and paid	(3)					(3)
Repurchase of shares	0
Ending balance (in shares) at Jun. 30, 2020			56,943,979
Ending balance at Jun. 30, 2020	1,971		$ 1	1,488	46	436
Beginning balance (in shares) at Dec. 31, 2020			52,656,067
Beginning balance at Dec. 31, 2020	2,201		$ 1	1,346	47	807
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	149					149
Total other comprehensive income	7				7
Shares issued from Employee Stock Purchase Plan (in shares)			62,462
Stock-based compensation (in shares)			33,957
Stock-based compensation	4			4
Dividends declared and paid (in shares)			114
Dividends declared and paid	(3)					(3)
Ending balance (in shares) at Mar. 31, 2021			52,752,600
Ending balance at Mar. 31, 2021	2,358		$ 1	1,350	54	953
Beginning balance (in shares) at Dec. 31, 2020			52,656,067
Beginning balance at Dec. 31, 2020	2,201		$ 1	1,346	47	807
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	296
Total other comprehensive income	(2)
Ending balance (in shares) at Jun. 30, 2021			52,862,264
Ending balance at Jun. 30, 2021	2,498		$ 1	1,356	45	1,096
Beginning balance (in shares) at Mar. 31, 2021			52,752,600
Beginning balance at Mar. 31, 2021	2,358		$ 1	1,350	54	953
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	147					147
Total other comprehensive income	(9)				(9)
Shares issued from Employee Stock Purchase Plan (in shares)			44,245
Stock-based compensation (in shares)			65,298
Stock-based compensation	6			6
Dividends declared and paid (in shares)			121
Dividends declared and paid	(4)					(4)
Ending balance (in shares) at Jun. 30, 2021			52,862,264
Ending balance at Jun. 30, 2021	$ 2,498		$ 1	$ 1,356	$ 45	$ 1,096