Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Commitments And Contingencies [Line Items]
Lease rent expense	$ 0.6	$ 0.6	$ 2.0	$ 1.9
Accumulated deferred rent payable	2.3		2.3
Cost of Revenue [Member]
Commitments And Contingencies [Line Items]
Lease rent expense	0.4	0.4	1.2	1.2
Operating Expense [Member]
Commitments And Contingencies [Line Items]
Lease rent expense	$ 0.2	$ 0.2	$ 0.8	$ 0.7
Office Space [Member]
Commitments And Contingencies [Line Items]
Lease extension	10 years		10 years
Office Space [Member] | Minimum [Member]
Commitments And Contingencies [Line Items]
Lease expiration date			Jan. 07, 2019
Office Space [Member] | Maximum [Member]
Commitments And Contingencies [Line Items]
Lease expiration date			Mar. 31, 2027
Tower Space [Member] | Minimum [Member]
Commitments And Contingencies [Line Items]
Lease expiration date			Feb. 28, 2020
Tower Space [Member] | Maximum [Member]
Commitments And Contingencies [Line Items]
Lease expiration date			Jun. 30, 2026