CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDER'S EQUITY - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-in Capital	Retained Earnings	Other
Shares Outstanding at Dec. 31, 2022		49.5
Total stockholders’ equity at Dec. 31, 2022	$ 1,901.3	$ 0.5	$ 703.5	$ 1,200.0	$ (2.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	23.4		23.4
Employee stock purchase plan, shares		0.4
Employee stock purchase plan, value	11.1		11.1
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(14.2)		(14.2)
Vesting of restricted stock units, shares		0.0
Stock Repurchased and Retired During Period, Shares		(1.4)
Stock Repurchased and Retired During Period, Value	(107.0)		(21.0)	(86.0)
Foreign currency translation adjustments	2.4				2.4
Net income	109.6			109.6
Shares Outstanding at Jun. 30, 2023		48.5
Total stockholders’ equity at Jun. 30, 2023	1,926.6	$ 0.5	702.8	1,223.6	(0.3)
Shares Outstanding at Mar. 31, 2023		49.2
Total stockholders’ equity at Mar. 31, 2023	1,923.5	$ 0.5	714.4	1,210.3	(1.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	11.3		11.3
Employee stock purchase plan, shares		0.2
Employee stock purchase plan, value	0.0
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(10.0)		(10.0)
Vesting of restricted stock units, shares		0.0
Stock Repurchased and Retired During Period, Shares		(0.9)
Stock Repurchased and Retired During Period, Value	(59.7)		(12.9)	(46.8)
Foreign currency translation adjustments	1.4				1.4
Net income	60.1			60.1
Shares Outstanding at Jun. 30, 2023		48.5
Total stockholders’ equity at Jun. 30, 2023	1,926.6	$ 0.5	702.8	1,223.6	(0.3)
Shares Outstanding at Dec. 31, 2023		46.7
Total stockholders’ equity at Dec. 31, 2023	1,892.1	$ 0.5	696.0	1,195.6	0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	22.7		22.7
Employee stock purchase plan, shares		0.4
Employee stock purchase plan, value	9.5		9.5
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(10.0)		(10.0)
Vesting of restricted stock units, shares		0.0
Stock Repurchased and Retired During Period, Shares		(2.0)
Stock Repurchased and Retired During Period, Value	(189.4)		(31.0)	(158.4)
Foreign currency translation adjustments	(2.3)				(2.3)
Net income	85.3			85.3
Shares Outstanding at Jun. 30, 2024		45.1
Total stockholders’ equity at Jun. 30, 2024	1,807.9	$ 0.5	687.2	1,122.5	(2.3)
Shares Outstanding at Mar. 31, 2024		46.2
Total stockholders’ equity at Mar. 31, 2024	1,861.4	$ 0.5	695.7	1,165.4	(0.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	11.0		11.0
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(1.5)		(1.5)
Vesting of restricted stock units, shares		0.0
Stock Repurchased and Retired During Period, Shares		(1.1)
Stock Repurchased and Retired During Period, Value	(108.1)		(18.0)	(90.1)
Foreign currency translation adjustments	(2.1)				(2.1)
Net income	47.2			47.2
Shares Outstanding at Jun. 30, 2024		45.1
Total stockholders’ equity at Jun. 30, 2024	$ 1,807.9	$ 0.5	$ 687.2	$ 1,122.5	$ (2.3)