Accounts Receivable, Net Acounts Receivable, Net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2014
Current
Accounts receivable–billed	$ 378,691		$ 378,691		$ 395,509
Accounts receivable–unbilled	466,450		466,450		522,685
Allowance for doubtful accounts	(396)		(396)		(1,457)
Accounts receivable, net	844,745		844,745		916,737
Long-term
Unbilled receivables	18,284		18,284		22,877
Total accounts receivable, net	863,029		863,029		939,614
Provision for doubtful accounts	$ (8)	$ (302)	$ (987)	$ 1,200