Other Comprehensive Income and Accumulated Other Comprehensive Loss - Components of Other Comprehensive Income and Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at December 31, 2017		$ 616,030
Net current period other comprehensive income (loss)
Other comprehensive income (loss) before reclassifications	[1]	1,682	$ 372
Amounts reclassified from accumulated other comprehensive income (3)		(73)
Total current period other comprehensive income (loss)		1,609	372
Balance at March 31, 2018		622,501
Reclassification of stranded tax effects due to adoption of accounting principle		(829)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at December 31, 2017		(7,638)	(11,815)
Adjusted beginning balance		(8,945)
Net current period other comprehensive income (loss)
Other comprehensive income (loss) before reclassifications	[1]	1,237	372
Total current period other comprehensive income (loss)		1,237
Balance at March 31, 2018		(7,708)	(11,443)
Reclassification of stranded tax effects due to adoption of accounting principle		(1,307)
Gain on Sale of Interest Rate Hedge Agreement
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at December 31, 2017	[2]	2,158	2,175
Adjusted beginning balance	[2]	2,636
Net current period other comprehensive income (loss)
Amounts reclassified from accumulated other comprehensive income (3)	[2]	(73)
Total current period other comprehensive income (loss)	[2]	(73)
Balance at March 31, 2018	[2]	2,563	2,175
Reclassification of stranded tax effects due to adoption of accounting principle	[2]	478
Change in Fair Value of Interest Rate Hedge Agreement
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at December 31, 2017	[3]	441
Adjusted beginning balance	[3]	441
Net current period other comprehensive income (loss)
Other comprehensive income (loss) before reclassifications	[1],[3]	445
Total current period other comprehensive income (loss)	[3]	445
Balance at March 31, 2018	[3]	886
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at December 31, 2017		(5,039)	(9,640)
Adjusted beginning balance		(5,868)
Net current period other comprehensive income (loss)
Total current period other comprehensive income (loss)		1,609
Balance at March 31, 2018		$ (4,259)	$ (9,268)

[1] (3) - Net of tax totaling $0.3 million and $0.2 million for the three months ended March 31, 2018 and 2017, respectively.

[2] (1) - 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 as interest payments are made on the Credit Facility from January 31, 2018 to January 31, 2023.

[3] (2) - 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 as interest payments are made on the Credit Facility from August 31, 2018 to August 31, 2023.