Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss) (1)	$ 35,220	$ 220,439
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Foreign currency translation gains (losses) (1)	(24,203)	4,353
Defined benefit pension plans, net of tax	39	144
Defined benefit post-retirement plan adjustments	(39)	(47)
Equity interest in investee's other comprehensive income (loss)	(11)	5,573
Foreign exchange contracts	(4,438)	952
Other comprehensive income (loss) (1)	(28,652)	10,975
Total comprehensive income (loss) (1)	$ 6,568	$ 231,414