Income Taxes - Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Components of Income (loss) before income taxes
Domestic (U.S.)	$ 95,639	$ 141,582	$ (67)
Foreign (Outside U.S.)	74,792	45,485	9,875
Income before income taxes and equity income (loss) from equity method investments (1)	170,431	187,067	9,808
Current:
Federal	170	223	0
State and local	161	50	62
Foreign	9,966	8,295	4,247
Total current income tax expense from continuing operations	10,297	8,568	4,309
Deferred:
Federal	(43,804)	(807)	(6)
State and local	(773)	(96)	(97)
Foreign	(5,180)	1,467	88
Deferred tax expense (benefit) from continuing operations	(49,757)	564	(15)
Provision for income taxes	(39,460)	9,132	4,294
Latest Tax Year
Deferred:
Foreign	$ (50,100)	$ 600	$ 1,200