Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Cash flows from operating activities:
Net income	$ 15,073	$ 18,553	$ 75,657	$ 61,606	$ 48,379
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation			5,195	4,304	3,663
Amortization of capitalized software costs			8,254	7,091	5,927
Amortization of other intangibles			4,501	3,255	1,783
Provision for bad debts			5,715	3,780	3,465
Provision (recovery) for inventory obsolescence			43	27	27
Share-based compensation			3,321	3,748	2,073
Deferred income tax benefit			(8,025)	(4,194)	(786)
Tax benefit associated with stock options			4,145	1,524	1,576
Excess tax benefit from share-based compensation			(4,145)	(1,524)	(1,576)
Loss (gain) on disposal of equipment and improvements			73	(33)
Changes in assets and liabilities, net of amounts acquired:
Accounts receivable			(10,389)	(36,094)	(18,944)
Inventories			(1,825)	(620)	(238)
Income taxes receivable			(2,628)	2,953	3,875
Other current assets			(2,154)	(2,074)	(2,310)
Other assets			(841)	(1,817)	(894)
Accounts payable			(2,184)	3,344	(1,810)
Deferred revenue			5,993	13,211	12,528
Accrued compensation and related benefits			1,623	1,296	(1,006)
Income taxes payable			(3,530)	3,530	(1,404)
Other current liabilities			(3,229)	13,096	846
Deferred compensation			1,009	605	46
Other noncurrent liabilities			207	(6,950)
Net cash provided by operating activities			76,786	70,064	55,220
Cash flows from investing activities:
Additions to capitalized software costs			(13,098)	(10,695)	(7,921)
Additions to equipment and improvements			(10,323)	(6,804)	(4,935)
Proceeds for disposal of equipment and improvements			11	336
Proceeds from sale of marketable securities				7,700	425
Purchase of marketable securities				(1,120)
Cash acquired from Acquisition			10
Payment of contingent consideration related to purchase of PMP					(3,000)
Net cash used in investing activities			(34,904)	(10,583)	(13,945)
Cash flows from financing activities:
Excess tax benefit from share-based compensation			4,145	1,524	1,576
Proceeds from exercise of stock options			12,789	5,717	5,855
Dividends paid			(40,989)	(34,716)	(34,275)
Net cash used in financing activities			(24,055)	(27,475)	(26,844)
Net increase in cash and cash equivalents			17,827	32,006	14,431
Cash and cash equivalents at beginning of period			116,617	84,611	70,180
Cash and cash equivalents at end of period	134,444	116,617	134,444	116,617	84,611
Supplemental disclosures of cash flow information:
Cash paid during the period for income taxes, net of refunds			50,605	29,044	24,506
Non-cash investing activities:
Tenant improvement allowance received from landlord				1,970
Unrealized loss on marketable securities, net of tax			(1)
Common stock issued at fair value for Opus earnout settlement			11,888
Issuance of stock options in connection with the acquisition of PMP					433
CQI Solutions [Member]
Cash flows from investing activities:
Cash acquired from Acquisition			222
Purchase of CQI solutions			(2,737)
Effective November 14, 2011, July 26, 2011, April 29, 2011, February 10, 2010, August 12, 2009, the company acquired ViaTrack, CQI Solutions, IntraNexus, Opus and Sphere respectively in a transaction summarized as follows:
Fair value of net assets acquired	11,417	0	11,417	0	0
Cash paid	(2,737)	0	(2,737)	0	0
Common Stock issued at fair value	(2,864)	0	(2,864)	0	0
Purchase price holdback	(600)	0	(600)	0	0
Fair value of contingent consideration	(2,346)	0	(2,346)	0	0
Liabilities assumed	2,870	0	2,870	0	0
IntraNexus [Member]
Cash flows from investing activities:
Payment for acquiring businesses			(3,279)
Effective November 14, 2011, July 26, 2011, April 29, 2011, February 10, 2010, August 12, 2009, the company acquired ViaTrack, CQI Solutions, IntraNexus, Opus and Sphere respectively in a transaction summarized as follows:
Fair value of net assets acquired	4,524	0	4,524	0	0
Cash paid	(3,279)	0	(3,279)	0	0
Purchase price holdback	(125)	0	(125)	0	0
Fair value of contingent consideration	(800)	0	(800)	0	0
Liabilities assumed	320	0	320	0	0
ViaTrack [Member]
Cash flows from investing activities:
Payment for acquiring businesses			(5,710)
Effective November 14, 2011, July 26, 2011, April 29, 2011, February 10, 2010, August 12, 2009, the company acquired ViaTrack, CQI Solutions, IntraNexus, Opus and Sphere respectively in a transaction summarized as follows:
Fair value of net assets acquired	11,048	0	11,048	0	0
Cash paid	(5,710)	0	(5,710)	0	0
Common Stock issued at fair value	(1,068)	0	(1,068)	0	0
Purchase price holdback	(1,187)	0	(1,187)	0	0
Fair value of contingent consideration	(2,958)	0	(2,958)	0	0
Liabilities assumed	125	0	125	0	0
Opus [Member]
Cash flows from investing activities:
Cash acquired from Acquisition					2,036
Payment for acquiring businesses					(250)
Effective November 14, 2011, July 26, 2011, April 29, 2011, February 10, 2010, August 12, 2009, the company acquired ViaTrack, CQI Solutions, IntraNexus, Opus and Sphere respectively in a transaction summarized as follows:
Fair value of net assets acquired	0	0	0	0	32,209
Cash paid	0	0	0	0	(250)
Common Stock issued at fair value	0	0	0	0	(8,815)
Fair value of contingent consideration	0	0	0	0	(11,516)
Liabilities assumed	0	0	0	0	11,628
Sphere [Member]
Cash flows from investing activities:
Payment for acquiring businesses					(300)
Effective November 14, 2011, July 26, 2011, April 29, 2011, February 10, 2010, August 12, 2009, the company acquired ViaTrack, CQI Solutions, IntraNexus, Opus and Sphere respectively in a transaction summarized as follows:
Fair value of net assets acquired	0	0	0	0	1,453
Cash paid	0	0	0	0	(300)
Fair value of contingent consideration	0	0	0	0	(1,074)
Liabilities assumed	$ 0	$ 0	$ 0	$ 0	$ 79