Equity - Changes in AOCI/L by Component (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Apr. 01, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 963,802	$ 921,432	$ 850,757	$ 983,465
Change in AOCI/L before reclassifications to income	(6,731)	1,783	(37,146)	35,404
Reclassifications from AOCL/I to income	(1,054)	(416)	(4,251)	(60,187)
Other comprehensive (loss) income, net of tax	(7,785)	1,367	(41,397)	(24,783)
Ending balance	919,657	941,548	919,657	941,548
Interest Rate Swaps
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(46,990)	16,281	(7,770)	2,483
Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect				591
Change in AOCI/L before reclassifications to income	(10,285)	969	(46,224)	13,748
Reclassifications from AOCL/I to income	(1,094)	(619)	(4,375)	(191)
Other comprehensive (loss) income, net of tax	(11,379)	350	(50,599)	13,557
Ending balance	(58,369)	16,631	(58,369)	16,631
Defined Benefit Pension Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(5,655)	(5,750)	(5,738)	(5,861)
Change in AOCI/L before reclassifications to income	0	0	0	0
Reclassifications from AOCL/I to income	41	53	124	164
Other comprehensive (loss) income, net of tax	41	53	124	164
Ending balance	(5,614)	(5,697)	(5,614)	(5,697)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(20,834)	(34,582)	(26,359)	4,886
Change in AOCI/L before reclassifications to income	3,553	814	9,078	21,656
Reclassifications from AOCL/I to income	0	150	0	(60,160)
Other comprehensive (loss) income, net of tax	3,553	964	9,078	(38,504)
Ending balance	(17,281)	(33,618)	(17,281)	(33,618)
Accumulated Other Comprehensive Loss, Net
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(73,479)	(24,051)	(39,867)	1,508
Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect				591
Other comprehensive (loss) income, net of tax	(7,785)	1,367	(41,397)	(24,783)
Ending balance	(81,264)	(22,684)	(81,264)	(22,684)
Accumulated Earnings
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	1,879,633	1,659,658	1,755,432	1,647,284
Ending balance	$ 1,921,021	$ 1,671,412	$ 1,921,021	$ 1,671,412
Accounting Standards Update 2018-02
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Adoption of ASU					$ 0
Accounting Standards Update 2018-02 \| Accumulated Other Comprehensive Loss, Net
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Adoption of ASU					591
Accounting Standards Update 2018-02 \| Accumulated Earnings
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Adoption of ASU					$ (591)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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Amount of increase (decrease) in accumulated other comprehensive income (AOCI) for reclassification to retained earnings of tax effect from remeasurement of deferred tax pursuant to Tax Cuts and Jobs Act.

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