Stock Repurchases - USD ($)		3 Months Ended	6 Months Ended
		Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Mar. 05, 2020
Equity, Class of Treasury Stock [Line Items]
Common stock repurchased, shares			991,571	725,220
Common stock repurchased, value		$ 254,500,000	$ 389,700,000	$ 307,100,000
Increase in number of shares authorized for repurchase					3,000,000
Remaining number of shares authorized for repurchase		1,518,105	1,518,105
Open Market [Member]
Equity, Class of Treasury Stock [Line Items]
Common stock repurchased, shares	[1]		984,505	710,157
Common stock repurchased, value	[1]		$ 387,000,000.0	$ 300,600,000
Other [Member]
Equity, Class of Treasury Stock [Line Items]
Common stock repurchased, shares	[2]		7,066	15,063
Common stock repurchased, value	[2]		$ 2,700,000	$ 6,500,000

[1] Represents repurchases under authorizations by the board of directors for the repurchase of shares by us from time to time in the open market or in privately negotiated transactions. On March 5, 2020, the board of directors authorized the repurchase of up to three million shares of our common stock in addition to the board’s prior authorizations. As of June 30, 2021, we had authorization to repurchase 1,518,105 shares of our common stock.

[2] Represents shares of common stock released to us by team members as payment of tax withholdings upon the vesting of restricted stock and restricted stock units and the conversion of restricted stock units to common stock.