Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($)	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)	$ 110,528,000	$ 56,769,000	$ 296,178,000	$ (180,517,000)
Other comprehensive (loss) income	(3,000)	784,000	(27,000)	350,000
Comprehensive income (loss)	$ 110,525,000	$ 57,553,000	$ 296,151,000	$ (180,167,000)