Consolidated Statements of Shareholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock	Additional Paid-in Capital	Retained Earnings
Beginning Balance at Mar. 31, 2009	$ 155,567	$ 568	$ 103,240	$ 51,759
Beginning Balance, Shares at Mar. 31, 2009		56,894,000
Exercise of stock options and vesting of restricted stock	5,855	6	5,849
Exercise of stock options and vesting of restricted stock, Shares	475,206	476,000
Tax benefit resulting from exercise of stock options	1,576		1,576
Stock-based compensation	2,073		2,073
Stock-based compensation related to acquisitions	433		433
Common stock issuance for acquisitions	8,815	4	8,811
Common stock issuance for acquisitions, Shares		388,000
Dividends declared	(34,409)			(34,409)
Net income	48,379			48,379
Ending Balance at Mar. 31, 2010	188,289	578	121,982	65,729
Ending Balance, Shares at Mar. 31, 2010		57,758,000
Exercise of stock options and vesting of restricted stock	5,717	3	5,714
Exercise of stock options and vesting of restricted stock, Shares	307,428	310,000
Tax benefit resulting from exercise of stock options	1,524		1,524
Stock-based compensation	3,748		3,748
Dividends declared	(36,214)			(36,214)
Net income	61,606			61,606
Ending Balance at Mar. 31, 2011	224,670	581	132,968	91,121
Ending Balance, Shares at Mar. 31, 2011		58,068,000
Exercise of stock options and vesting of restricted stock	12,745	7	12,738
Exercise of stock options and vesting of restricted stock, Shares	697,157	735,000
Common stock issuance for Opus earnout settlement	11,888	3	11,885
Common stock issuance for Opus earnout settlement, Shares		286,000
Tax benefit resulting from exercise of stock options	4,145		4,145
Stock-based compensation	3,321		3,321
Common stock issuance for acquisitions	3,932	1	3,931
Common stock issuance for acquisitions, Shares		91,000
Dividends declared	(41,181)			(41,181)
Net income	75,657			75,657
Ending Balance at Mar. 31, 2012	$ 295,177	$ 592	$ 168,988	$ 125,597
Ending Balance, Shares at Mar. 31, 2012		59,180,000