Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	[1],[2]	$ 40,806	$ 18,589	$ 113,167	$ 251,847
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Foreign currency translation gains (losses)	[2]	(5,152)	6,516	(32,504)	20,481
Defined benefit pension plans, net of tax		139	147	426	(6)
Defined benefit post-retirement plan adjustments		(38)	(47)	(116)	(141)
Equity interest in investee's other comprehensive income (loss)		8	(5)	(9)	5,568
Foreign exchange contracts		(2,605)	(5,330)	(1,855)	(6,807)
Other Comprehensive Income (Loss), Net of Tax		(1,835)	0	(1,835)	0
Other comprehensive income (loss)	[2]	(9,483)	1,281	(35,893)	19,095
Total comprehensive income (loss)	[2]	$ 31,323	$ 19,870	$ 77,274	$ 270,942

[1] Three and nine months ended December 31, 2017 adjusted due to the adoption of ASC 606.

[2] Three and nine months ended December 31, 2017 adjusted due to the adoption of ASC 606.