Basis of Presentation - Revenues by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total revenues	$ 588,224	$ 554,694	$ 1,717,517	$ 1,511,037
U.S. Customers [Member]
Segment Reporting Information [Line Items]
Total revenues	523,455	492,681	1,521,022	1,341,073
Non U.S. Customers [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 64,769	$ 62,013	$ 196,495	$ 169,964