Schedule of Fixed Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016
Fixed assets:
Total cost	$ 668,194	$ 643,457
Less: accumulated depreciation and amortization	(497,390)	(480,152)
Fixed assets, net	170,804	163,305
Equipment
Fixed assets:
Total cost	156,598	150,259
Software
Fixed assets:
Total cost	296,866	293,844
Leasehold improvements
Fixed assets:
Total cost	$ 214,730	$ 199,354