Accumulated Other Comprehensive (Loss) Income - Activity in AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,855,657	$ 642,817	$ 706,755	$ (186,924)
Other comprehensive loss	(6,806)	(2,253)	(11,268)	(7,212)
Ending balance	1,838,579	731,003	1,838,579	731,003
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(16,977)	(5,189)	(12,515)	(230)
Ending balance	(23,783)	(7,442)	(23,783)	(7,442)
Pension and other postretirement benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(6,976)	(6,129)	(8,027)	(7,126)
Other comprehensive loss	525	618	1,576	1,615
Ending balance	(6,451)	(5,511)	(6,451)	(5,511)
Pension and other postretirement benefits, gain (loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Other comprehensive (loss) income, before reclassifications, before tax	517	614	1,551	1,592
Other comprehensive (loss) income, before reclassifications, tax	0	0	0	0
Other comprehensive (loss) income, before reclassifications	517	614	1,551	1,592
Pension and other postretirement benefits, prior service cost
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Amount reclassified from AOCI to net income/loss	8	4	25	23
Less: Tax expense	0	0	0	0
Net amount reclassified from AOCI to net income	8	4	25	23
Foreign currency translation adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(4,358)	2,122	(3,322)	8,318
Other comprehensive (loss) income, before reclassifications, before tax	(5,089)	(2,953)	(6,125)	(9,149)
Amount reclassified from AOCI to net income/loss	(2,605)	0	(2,605)	0
Less: Tax expense	0	0	0	0
Other comprehensive loss	(7,694)	(2,953)	(8,730)	(9,149)
Ending balance	(12,052)	(831)	(12,052)	(831)
Cash flow hedge derivatives
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(5,643)	(1,182)	(1,166)	(1,422)
Other comprehensive (loss) income, before reclassifications, before tax	6,087	(76)	2,103	(464)
Other comprehensive (loss) income, before reclassifications, tax	0	128	0	173
Other comprehensive (loss) income, before reclassifications	6,087	(204)	2,103	(637)
Ending balance	(5,280)	(1,100)	(5,280)	(1,100)
Cash flow hedge derivatives | Interest expense
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Net amount reclassified from AOCI to net income	(212)	286	(212)	959
Cash flow hedge derivatives | Foreign currency exchange gain, net
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Net amount reclassified from AOCI to net income	$ (5,512)	$ 0	$ (6,005)	$ 0