Other Comprehensive Income (Loss) and Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019		Mar. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Balance		$ 660,417		$ 616,030
Current period other comprehensive (loss) income:
Total current period other comprehensive (loss) income		283		1,609
Balance		662,571		622,501
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Balance		(14,168)		(7,638)
Reclassification of stranded tax effects due to adoption of accounting principle	[1]			(1,307)
Adjusted beginning balance					$ (8,945)
Current period other comprehensive (loss) income:
Other comprehensive income (loss) before reclassifications		1,254		1,578
Effect of taxes	[2]			(341)
Total current period other comprehensive (loss) income		1,254		1,237
Balance		(12,914)		(7,708)
Gain on Sale of Interest Rate Hedge Agreement
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	[3]	2,164		2,158
Reclassification of stranded tax effects due to adoption of accounting principle	[1],[3]			478
Adjusted beginning balance	[3]				2,636
Current period other comprehensive (loss) income:
Amounts reclassified from accumulated other comprehensive income	[3]	(180)		(120)
Effect of taxes	[2],[3]	47		47
Total current period other comprehensive (loss) income	[3]	(133)		(73)
Balance	[3]	2,031		2,563
Change in Fair Value of Interest Rate Hedge Agreements
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	[4]	(547)	[5]	441
Adjusted beginning balance	[4]				441
Current period other comprehensive (loss) income:
Other comprehensive income (loss) before reclassifications	[4]	(1,164)	[5]	445
Amounts reclassified from accumulated other comprehensive income	[4],[5]	23
Effect of taxes	[2],[4],[5]	303
Total current period other comprehensive (loss) income	[4]	(838)	[5]	445
Balance	[4]	(1,385)	[5]	886
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Balance		(12,551)		(5,039)
Reclassification of stranded tax effects due to adoption of accounting principle	[1]			(829)
Adjusted beginning balance					$ (5,868)
Current period other comprehensive (loss) income:
Other comprehensive income (loss) before reclassifications		90		2,023
Amounts reclassified from accumulated other comprehensive income		(157)		(120)
Effect of taxes	[2]	350		(294)
Total current period other comprehensive (loss) income		283		1,609
Balance		$ (12,268)		$ (4,259)

[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] The Company’s effective tax rate for the three months ended March 31, 2019 and 2018 was 19.5% and 22.5%, respectively.

[3] Represents the unamortized 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, at the date of the sale, was recorded in other comprehensive income, net of tax, and is being reclassified to interest expense 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 interest rate hedge agreements designated as a cash flow hedge. The fair value of the interest rate hedge agreements was recorded in other comprehensive income and will be reclassified to interest expense 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.

[5] The fair value of the fixed interest rate swap asset is included in other liabilities on the consolidated balance sheet.