Income Tax (Tables)

12 Months Ended

Mar. 31, 2012

Income Tax [Abstract]

Provision (benefit) for income taxes

	Fiscal Year Ended March 31,
	2012			2011			2010
Current:
Federal taxes	$	36,109		$	28,979		$	23,750
State taxes		8,614			6,501			5,043
Foreign taxes		73			—			—
Total current taxes		44,796			35,480			28,793
Deferred:
Federal taxes	$	(3,571	)	$	(2,168	)	$	(768	)
State taxes		(502	)		(502	)		(186	)
Foreign taxes		(73	)		—			—
Total deferred taxes		(4,146	)		(2,670	)		(954	)
Provision for income taxes	$	40,650		$	32,810		$	27,839

Provision for income taxes differ at the federal statutory rate

	Fiscal Year Ended March 31,
	2012			2011			2010
Current:
Federal income tax statutory rate		35.0	%		35.0	%		35.0	%
Increase (decrease) resulting from:
State income taxes, net of Federal benefit		4.5			4.1			4.3
Research and development tax credits		(0.9	)		(1.0	)		(0.9	)
Qualified production activities income deduction		(3.0	)		(3.0	)		(2.0	)
Other		(0.6	)		(0.3	)		0.1
Effective income tax rate		35.0	%		34.8	%		36.5	%

Net deferred tax assets and liabilities in consolidated balance sheets

	March 31, 2012			March 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	)

Reconciliation of beginning and ending amount of unrecognized tax benefits

Balance at March 31, 2010	$	656
Additions for prior year tax positions		34
Reductions for prior year tax positions		(18	)
Balance at March 31, 2011	$	672
Additions for prior year tax positions		26
Reductions for prior year tax positions		(285	)
Balance at March 31, 2012	$	413