Consolidated Statements of Stockholders' Equity and Redeemable Noncontrolling Interest Statement (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income
Redeemable noncontrolling interest, beginning balance at Mar. 31, 2010	$ 34,578
Beginning balance at Mar. 31, 2010	145,776	65	127,152	18,559	0
Beginning balance, common stock, shares at Mar. 31, 2010		6,541,684
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,831	0	0	2,831	0
Stock option exercises and associated tax benefits, shares		275,922
Stock option exercises and associated tax benefits, amount	1,391	3	1,388	0	0
Stock-based compensation	671	0	671	0	0
Increase (Decrease) in Redeemable Noncontrolling Interest [Roll Forward]
Net income	1,241
Redeemable noncontrolling interest, ending balance at Mar. 31, 2011	35,819
Ending balance at Mar. 31, 2011	150,669	68	129,211	21,390	0
Ending balance, common stock, shares at Mar. 31, 2011		6,817,606
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	15,237	0	0	15,237	0
Unrealized gain on available-for-sale securities	58	0	0	0	58
Stock option exercises and associated tax benefits, shares		73,190
Stock option exercises and associated tax benefits, amount	1,463	1	1,462	0	0
Stock-based compensation	916	0	916	0	0
Increase (Decrease) in Redeemable Noncontrolling Interest [Roll Forward]
Net income	14,491
Other comprehensive income	58
Capital contribution through conversion of notes payable	36,173
Redeemable noncontrolling interest, ending balance at Mar. 31, 2012	86,541
Ending balance at Mar. 31, 2012	168,343	69	131,589	36,627	58
Ending balance, common stock, shares at Mar. 31, 2012	6,890,796	6,890,796
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,963	0	0		0
Unrealized gain on available-for-sale securities	119	0	0	0	119
Stock option exercises and associated tax benefits, shares		77,158
Stock option exercises and associated tax benefits, amount	2,199	1	2,198	0	0
Stock-based compensation	1,266	0	1,266	0	0
Increase (Decrease) in Redeemable Noncontrolling Interest [Roll Forward]
Net income	5,334
Other comprehensive income	119
Redeemable noncontrolling interest, ending balance at Mar. 30, 2013	91,994
Ending balance at Mar. 30, 2013	$ 176,890	$ 70	$ 135,053	$ 41,590	$ 177
Ending balance, common stock, shares at Mar. 30, 2013	6,967,954