Schedule of Fixed Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Mar. 31, 2015
Fixed assets:
Total cost	$ 644,059	$ 626,058
Less: accumulated depreciation and amortization	(476,318)	(446,452)
Fixed assets, net	167,741	179,606
Equipment
Fixed assets:
Total cost	152,758	152,893
Software
Fixed assets:
Total cost	294,096	269,745
Leasehold improvements
Fixed assets:
Total cost	$ 197,205	$ 203,420