Other Comprehensive Income (Loss) and Accumulated Other Comprehensive Loss - Components of Other Comprehensive Income and Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 30, 2018		Jun. 30, 2017		Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive (loss) income						$ 616,030
Current period other comprehensive income (loss):
Total current period other comprehensive (loss) income		$ (3,317)		$ 2,100		(1,708)	$ 2,472
Accumulated other comprehensive (loss) income		635,371				635,371
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive (loss) income		(7,708)		(11,443)		(7,638)	(11,815)
Reclassification of stranded tax effects due to adoption of accounting principle	[1]					(1,307)
Adjusted beginning balance						(8,945)
Current period other comprehensive income (loss):
Other comprehensive (loss) income before reclassifications		(3,366)		2,100	[2]	(2,129)	2,472
Total current period other comprehensive (loss) income		(3,366)	[2]			(2,129)
Accumulated other comprehensive (loss) income		(11,074)		(9,343)		(11,074)	(9,343)
Gain on Sale of Interest Rate Hedge Agreement
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive (loss) income	[3]	2,563		2,175		2,158	2,175
Reclassification of stranded tax effects due to adoption of accounting principle	[1],[3]					478
Adjusted beginning balance	[3]					2,636
Current period other comprehensive income (loss):
Amounts reclassified from accumulated other comprehensive income	[3]	(132)				(205)
Total current period other comprehensive (loss) income	[3]	(132)	[2]			(205)
Accumulated other comprehensive (loss) income	[3]	2,431		2,175		2,431	2,175
Change in Fair Value of Interest Rate Hedge Agreement
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive (loss) income	[4]	886				441
Adjusted beginning balance	[4]					441
Current period other comprehensive income (loss):
Other comprehensive (loss) income before reclassifications	[4]	181				626
Total current period other comprehensive (loss) income	[4]	181	[2]			626
Accumulated other comprehensive (loss) income	[4]	1,067				1,067
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive (loss) income		(4,259)		(9,268)		(5,039)	(9,640)
Reclassification of stranded tax effects due to adoption of accounting principle	[1]					(829)
Adjusted beginning balance						(5,868)
Current period other comprehensive income (loss):
Other comprehensive (loss) income before reclassifications		(3,185)		2,100	[2]	(1,503)	2,472
Amounts reclassified from accumulated other comprehensive income		(132)				(205)
Total current period other comprehensive (loss) income		(3,317)	[2]			(1,708)
Accumulated other comprehensive (loss) income		$ (7,576)		$ (7,168)		$ (7,576)	$ (7,168)

[1] The Company has adjusted the balance at December 31, 2017 of accumulated other comprehensive loss for the stranded tax effects caused by the enactment of the Tax Act.

[2] Changes in other comprehensive income (loss) are shown net of a total tax benefit of $0.2 million and tax expense of $0.5 million for the three-months ended June 30, 2018 and 2017, respectively, and total tax expense of $0.1 million and $0.7 million for the six-months ended June 30,2018 and 2017, respectively

[3] Represents the fair value of an interest rate hedge agreement, designated as a cash flow hedge, which was sold on December 1, 2016. The fair value of the interest rate hedge agreement was recorded in other comprehensive income, net of tax, and will be reclassified to earnings when earnings are impacted by the hedged items and as interest payments are made on the Credit Facility from January 31, 2018 to January 31, 2023.

[4] Represents the change in fair value of an interest rate hedge agreement designated as a cash flow hedge, and entered into on August 31, 2017. The fair value of the interest rate hedge agreement was recorded in other comprehensive income and will be reclassified to earnings when earnings are impacted by the hedged items and as interest payments are made on the Credit Facility from August 31, 2018 to August 31, 2023.