Reclassifications Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	$ 732,573
Total amount reclassified from Accumulated other comprehensive loss, net of tax	720	$ 15,359
Reclassification due to the adoption of ASU 2018-02			$ 0	$ (3,772)
Other comprehensive income (loss)	(19,187)	18,279
Balance at end of period	719,382
Accumulated Defined Benefit Plans Adjustment Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(124,848)	(115,517)
Tax benefit	(1,067)	(666)
Total amount reclassified from Accumulated other comprehensive loss, net of tax	3,102	2,023
Balance at end of period	(121,746)	(117,266)
Accumulated Defined Benefit Plans Adjustment Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	0	0
Tax benefit	0	0
Total amount reclassified from Accumulated other comprehensive loss, net of tax	0	0
Balance at end of period	0	0
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Amounts reclassified from Accumulated other comprehensive loss	(52)	(105)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Amounts reclassified from Accumulated other comprehensive loss	0	0
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Amounts reclassified from Accumulated other comprehensive loss	4,221	2,794
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Amounts reclassified from Accumulated other comprehensive loss	0	0
Accumulated Net Investment Gain (Loss) Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	6	(572)
Other comprehensive income (loss)	(62)	536
Balance at end of period	(56)	(36)
Accumulated Net Investment Gain (Loss) Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period		0
Other comprehensive income (loss)		0
Balance at end of period	0	0
Accumulated Foreign Currency Adjustment Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(89,161)	(102,838)
Total amount reclassified from Accumulated other comprehensive loss, net of tax	720	15,359
Other comprehensive income (loss)	(22,832)	218
Balance at end of period	(111,273)	(87,261)
Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	423	496
Total amount reclassified from Accumulated other comprehensive loss, net of tax	0	0
Other comprehensive income (loss)	(115)	143
Balance at end of period	$ 308	$ 639