Income Tax (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Mar. 31, 2011
Deferred tax assets:
Deferred revenue	$ 8,618	$ 5,715
Inventory valuation	113	122
Purchased in-process research and development
Accrued compensation and benefits	3,788	3,180
Deferred compensation	1,455	1,078
State income taxes	255	452
Compensatory stock option expense	1,828	1,759
Allowance for doubtful accounts	4,235	2,931
Other	4,813	1,071
Total deferred tax assets	25,105	16,308
Deferred tax liabilities:
Accelerated depreciation	(2,319)	(2,181)
Capitalized software	(7,797)	(5,913)
Intangibles assets	(7,307)	(6,132)
Prepaid expense	(2,979)	(3,069)
Other	73
Total deferred tax liabilities	(20,329)	(17,295)
Deferred tax assets (liabilities), net	$ 4,776	$ (987)