Other Comprehensive Loss - After-tax Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 128,688	$ 109,596	$ 109,596
Net current period change	(4,805)	104
Derivative equity	(2,778)	339
Amortization of actuarial losses	(447)	(649)
Ending balance	96,926	120,065	128,688
Foreign currency translation adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(24,032)	(22,847)	(22,847)
Net current period change	(4,805)	104
Derivative equity	0	0
Amortization of actuarial losses	0	0
Ending balance	(28,837)	(22,743)	(24,032)
Derivative instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	464	496	496
Net current period change	0	0
Derivative equity	(2,778)	339
Amortization of actuarial losses	0	0
Ending balance	(2,314)	835	464
Pension and post-retirement benefits plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(22,382)	(25,120)	(25,120)
Net current period change	0	0
Derivative equity	0	0
Amortization of actuarial losses	(447)	(649)
Ending balance	(22,829)	(25,769)	(22,382)
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(45,950)	(47,471)	(47,471)
Ending balance	$ (53,980)	$ (47,677)	$ (45,950)