Revenue Recognition - Narrative (Details) - USD ($)	3 Months Ended	6 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Apr. 01, 2018	Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Capitalized contract cost, amortization period	3 years	3 years
Reduction to accumulated deficit due to adoption of new accounting guidance	$ (278,622,000)	$ (278,622,000)		$ (305,484,000)
Contract asset impairment		0
Recognized revenue that was previously included in deferred revenue balances	83,200,000	131,500,000
Capitalized contract cost, amortization	6,100,000	11,800,000
Acquisition costs expensed as incurred	1,700,000	3,200,000
Accounting Standards Update 2014-09 | Effect of Change Higher (Lower)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reduction to accumulated deficit due to adoption of new accounting guidance	$ 46,773,000	$ 46,773,000	$ 40,800,000
Recognition of capitalized contract costs, due to adoption of new accounting guidance			$ 40,600,000