Changes in Accumulated Other Comprehensive Income (Loss) - Summary (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	$ 369,275	$ 353,396
Other comprehensive income (loss)	(802)	2,647
Amounts reclassified from accumulated other comprehensive loss	215	198
Balance at end of period	373,214	369,833
Loss reclassified from AOCI for defined benefit pension plans	200	200
Tax benefit reclassified from AOCI for defined benefit pension plans	100	100
Total Accumulated Other Comprehensive (Loss) Income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(42,685)	(20,148)
Balance at end of period	(43,272)	(17,303)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(18,458)	(2,221)
Other comprehensive income (loss)	(127)	2,545
Amounts reclassified from accumulated other comprehensive loss	0	0
Balance at end of period	(18,585)	324
Defined Benefit Pension Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(22,253)	(18,049)
Other comprehensive income (loss)	0	0
Amounts reclassified from accumulated other comprehensive loss	215	198
Balance at end of period	(22,038)	(17,851)
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(1,974)	122
Other comprehensive income (loss)	(675)	102
Amounts reclassified from accumulated other comprehensive loss	0	0
Balance at end of period	$ (2,649)	$ 224