Schedule of Fixed Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015
Fixed assets:
Total cost	$ 635,550	$ 626,058
Less: accumulated depreciation and amortization	(459,653)	(446,452)
Fixed assets, net	175,897	179,606
Equipment
Fixed assets:
Total cost	153,974	152,893
Software
Fixed assets:
Total cost	277,251	269,745
Leasehold improvements
Fixed assets:
Total cost	$ 204,325	$ 203,420