Schedule of Fixed Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Mar. 31, 2017
Fixed assets:
Total cost	$ 676,973	$ 668,596
Less: accumulated depreciation and amortization	(520,965)	(508,934)
Fixed assets, net	156,008	159,662
Equipment
Fixed assets:
Total cost	162,315	159,102
Software
Fixed assets:
Total cost	309,590	304,943
Leasehold improvements
Fixed assets:
Total cost	$ 205,068	$ 204,551