Changes in Accumulated Other Comprehensive Income (Loss) - Changes in AOCI by Component (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Changes in accumulated other comprehensive loss by component
Total other comprehensive (loss) income	$ (293,190)	$ 34,620	$ (318,629)	$ 103,685
Changes related to cash flow derivative hedges
Changes in accumulated other comprehensive loss by component
Accumulated comprehensive loss at beginning of the year			(537,216)	(250,355)
Other comprehensive income (loss) before reclassifications			(271,726)	106,505
Amounts reclassified from accumulated other comprehensive loss			(16,389)	4,071
Total other comprehensive (loss) income			(288,115)	110,576
Ending balance	(825,331)	(139,779)	(825,331)	(139,779)
Changes in defined benefit plans
Changes in accumulated other comprehensive loss by component
Accumulated comprehensive loss at beginning of the year			(26,023)	(33,666)
Other comprehensive income (loss) before reclassifications			(23,408)	5,863
Amounts reclassified from accumulated other comprehensive loss			577	1,086
Total other comprehensive (loss) income			(22,831)	6,949
Ending balance	(48,854)	(26,717)	(48,854)	(26,717)
Foreign currency translation adjustments
Changes in accumulated other comprehensive loss by component
Accumulated comprehensive loss at beginning of the year			(64,495)	(50,244)
Other comprehensive income (loss) before reclassifications			(7,683)	(13,840)
Amounts reclassified from accumulated other comprehensive loss			0	0
Total other comprehensive (loss) income			(7,683)	(13,840)
Ending balance	(72,178)	(64,084)	(72,178)	(64,084)
Accumulated other comprehensive loss
Changes in accumulated other comprehensive loss by component
Accumulated comprehensive loss at beginning of the year			(627,734)	(334,265)
Other comprehensive income (loss) before reclassifications			(302,817)	98,528
Amounts reclassified from accumulated other comprehensive loss			(15,812)	5,157
Total other comprehensive (loss) income			(318,629)	103,685
Ending balance	$ (946,363)	$ (230,580)	$ (946,363)	$ (230,580)

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

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