Consolidated Statements of Shareholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Mar. 31, 2011	$ 224,670	$ 581	$ 132,968	$ 91,121	$ 0
Beginning Balance, Shares at Mar. 31, 2011		58,068,000
Exercise of stock options and vesting of restricted stock	12,790	7	12,783
Exercise of stock options and vesting of restricted stock, Shares	697,157	735,000
Common stock issuance for earnout settlement	11,888	3	11,885
Common stock issuance for earnout settlement, Shares		286,000
Common stock issuance for acquisitions	3,932	1	3,931
Common stock issuance for acquisitions, Shares		91,000
Tax benefit resulting from exercise of stock options	4,145		4,145
Stock-based compensation	3,321		3,321
Dividends declared	(41,181)			(41,181)
Unrealized loss on AFS securities	(42)				(42)
Translation adjustments	(3)				(3)
Net income	75,657			75,657
Ending Balance at Mar. 31, 2012	295,177	592	169,033	125,597	(45)
Ending Balance, Shares at Mar. 31, 2012		59,180,000
Exercise of stock options and vesting of restricted stock	948	1	947
Exercise of stock options and vesting of restricted stock, Shares	56,366	83,000
Common stock issuance for earnout settlement	3,000	1	2,999
Common stock issuance for earnout settlement, Shares		165,000
Common stock issuance for acquisitions	4,595	1	4,594
Common stock issuance for acquisitions, Shares		115,000
Tax benefit resulting from exercise of stock options	(157)		(157)
Stock-based compensation	2,327		2,327
Dividends declared	(41,599)			(41,599)
Unrealized loss on AFS securities	0
Translation adjustments	34				34
Net income	42,724			42,724
Ending Balance at Mar. 31, 2013	307,049	595	179,743	126,722	(11)
Ending Balance, Shares at Mar. 31, 2013		59,543,000
Exercise of stock options and vesting of restricted stock	2,201	2	2,199
Exercise of stock options and vesting of restricted stock, Shares	111,272	167,000
Common stock issuance for earnout settlement	1,376	1	1,375
Common stock issuance for earnout settlement, Shares		62,000
Common stock issuance for acquisitions	9,273	4	9,269
Common stock issuance for acquisitions, Shares		434,000
Tax benefit resulting from exercise of stock options	(337)		(337)
Stock-based compensation	2,490		2,490
Dividends declared	(42,471)			(42,471)
Unrealized loss on AFS securities	(64)				(64)
Translation adjustments	(107)				(107)
Net income	15,680			15,680
Ending Balance at Mar. 31, 2014	$ 295,090	$ 602	$ 194,739	$ 99,931	$ (182)
Ending Balance, Shares at Mar. 31, 2014		60,206,000