Revenue Recognition - Schedule of Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2018	Mar. 31, 2018
Contract Asset
Balance as of March 31, 2018	$ 8,878	$ 11,251
Change in estimate of sales returns, net of sales recognized	12,277
Actual returns	(14,650)
Balance as of September 30, 2018	8,878
Contract Liability
Balance as of March 31, 2018	20,716	$ 23,156
Change in estimate of sales returns, net of sales recognized	38,098
Actual returns	(40,538)
Balance as of September 30, 2018	$ 20,716