Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 12,224	$ (95,831)	$ 23,341	$ (97,512)
Foreign currency translation adjustments	(17,073)	(3,217)	(20,452)	(23,693)
Net change in:
Deferred gains on cash flow hedges, net of taxes of $(873), $(582), $(1,629) and $(1,718), respectively	2,365	1,616	4,608	4,363
Unrecognized retirement obligations, net of taxes of $(220), $(1,932), $(1,606) and $(3,874), respectively	2,817	21,572	7,657	27,668
Other comprehensive income (loss)	(11,891)	19,971	(8,187)	8,338
Comprehensive income (loss)	$ 333	$ (75,860)	$ 15,154	$ (89,174)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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