Basis of Presentation - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended	9 Months Ended
	Aug. 31, 2017	Apr. 30, 2017	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016
Basis Of Presentation [Line Items]
Repurchases of common stock, value				$ 95,260,000	$ 0
Share Repurchase Program
Basis Of Presentation [Line Items]
Repurchases of outstanding common stock, shares			300,331	1,342,786
Repurchases of common stock, value			$ 8,300,000	$ 34,700,000
Stock repurchase program, expiration date		2018-04
Senior Secured Revolving Credit Facility
Basis Of Presentation [Line Items]
Share repurchases funding through borrowings	$ 40,000,000
Cinven
Basis Of Presentation [Line Items]
Repurchases of outstanding common stock, shares	2,000,000
Repurchases of common stock, value	$ 60,500,000
Purchase price of repurchased shares	$ 30.27
Maximum
Basis Of Presentation [Line Items]
Stock repurchase program, authorized amount		$ 50,000,000
Maximum | Accounting Standard Update (“ASU”) No. 2016-09
Basis Of Presentation [Line Items]
Discrete adjustments to income tax expense recognized				$ 100,000