Condensed Consolidating Financial Statements (Details) (USD $)	6 Months Ended
	Sep. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Mar. 31, 2011
Current assets:
Cash and cash equivalents	$ 160,495,000	$ 210,521,000	$ 127,163,000	$ 152,051,000
Accounts receivable, net	99,160,000	104,950,000
Inventories, net	224,773,000	212,234,000
Prepaid expenses and other	41,041,000	32,259,000
Deferred income taxes	5,658,000	6,370,000
Total current assets	531,127,000	566,334,000
Property and equipment, net	316,182,000	315,848,000
Goodwill	35,584,000	36,676,000	36,676,000
Intangible assets, net	40,102,000	41,527,000
Other assets	17,802,000	15,167,000
Total assets	940,797,000	975,552,000
Current liabilities:
Current portion of long-term debt	1,576,000	1,951,000
Accounts payable, trade	82,156,000	74,404,000
Accrued expenses	88,623,000	89,079,000
Income taxes payable	622,000	2,256,000
Total current liabilities	172,977,000	167,690,000
Long-term debt, less current portion	359,621,000	345,380,000
Other non-current obligations	90,098,000	101,229,000
Deferred income taxes	4,788,000	2,257,000
Stockholders' equity	313,313,000	358,996,000
Total liabilities and stockholders' equity	940,797,000	975,552,000
Parent
Current assets:
Cash and cash equivalents	8,398,000	7,933,000	6,705,000	6,417,000
Intercompany receivable	268,826,000	251,970,000
Prepaid expenses and other	276,000	306,000
Total current assets	277,500,000	260,209,000
Property and equipment, net	14,000	20,000
Investments in subsidiaries	431,379,000	454,517,000
Other assets	7,404,000	7,796,000
Long-term intercompany receivable	76,659,000	79,185,000
Total assets	792,956,000	801,727,000
Current liabilities:
Accounts payable, trade	57,000	460,000
Intercompany payable	60,976,000	34,830,000
Accrued expenses	35,523,000	30,747,000
Income taxes payable	(2,947,000)	(2,778,000)
Total current liabilities	93,609,000	63,259,000
Long-term debt, less current portion	359,066,000	343,539,000
Other non-current obligations	26,968,000	35,933,000
Stockholders' equity	313,313,000	358,996,000
Total liabilities and stockholders' equity	792,956,000	801,727,000
Guarantor Subsidiaries
Condensed Consolidating Balance Sheet
Percentage of ownership interest	100.00%
Interest rate of senior notes (as a percent)	10.50%
Retained earnings, intercompany receivables and net income understatement amount		27,800,000
Current assets:
Cash and cash equivalents	118,578,000	178,205,000	92,256,000	119,326,000
Accounts receivable, net	41,154,000	42,706,000
Intercompany receivable	214,603,000	55,863,000
Inventories, net	129,429,000	121,611,000
Prepaid expenses and other	14,258,000	13,537,000
Deferred income taxes	872,000	192,000
Total current assets	518,894,000	412,114,000
Property and equipment, net	114,612,000	114,615,000
Investments in subsidiaries	467,565,000	435,970,000
Goodwill	35,584,000	36,676,000
Intangible assets, net	30,899,000	31,630,000
Other assets	6,347,000	6,160,000
Long-term intercompany receivable	60,250,000	62,235,000
Total assets	1,234,151,000	1,099,400,000
Current liabilities:
Current portion of long-term debt	25,000	25,000
Accounts payable, trade	38,862,000	35,206,000
Intercompany payable	451,005,000	315,906,000
Accrued expenses	17,008,000	23,007,000
Income taxes payable	3,055,000	3,031,000
Total current liabilities	509,955,000	377,175,000
Other non-current obligations	4,504,000	5,400,000
Deferred income taxes	1,007,000	272,000
Long-term intercompany payable	76,659,000	79,185,000
Stockholders' equity	642,026,000	637,368,000
Total liabilities and stockholders' equity	1,234,151,000	1,099,400,000
Non-Guarantor Subsidiaries
Condensed Consolidating Balance Sheet
Percentage of capital stock	0.51
Current assets:
Cash and cash equivalents	33,519,000	24,383,000	28,202,000	26,308,000
Accounts receivable, net	58,006,000	62,244,000
Intercompany receivable	215,640,000	171,921,000
Inventories, net	95,344,000	90,623,000
Prepaid expenses and other	26,507,000	18,416,000
Deferred income taxes	4,786,000	6,178,000
Total current assets	433,802,000	373,765,000
Property and equipment, net	201,556,000	201,213,000
Investments in subsidiaries	10,678,000	(4,622,000)
Intangible assets, net	9,203,000	9,897,000
Other assets	4,051,000	1,211,000
Long-term intercompany receivable	2,881,000	1,065,000
Total assets	662,171,000	582,529,000
Current liabilities:
Current portion of long-term debt	1,551,000	1,926,000
Accounts payable, trade	43,237,000	39,490,000
Intercompany payable	159,226,000	122,799,000
Accrued expenses	36,092,000	35,325,000
Income taxes payable	514,000	2,003,000
Total current liabilities	240,620,000	201,543,000
Long-term debt, less current portion	555,000	1,841,000
Other non-current obligations	58,626,000	59,896,000
Deferred income taxes	3,781,000	1,985,000
Long-term intercompany payable	63,131,000	63,300,000
Stockholders' equity	295,458,000	253,964,000
Total liabilities and stockholders' equity	662,171,000	582,529,000
Reclassifications and Eliminations
Current assets:
Intercompany receivable	(699,069,000)	(479,754,000)
Total current assets	(699,069,000)	(479,754,000)
Investments in subsidiaries	(909,622,000)	(885,865,000)
Long-term intercompany receivable	(139,790,000)	(142,485,000)
Total assets	(1,748,481,000)	(1,508,104,000)
Current liabilities:
Accounts payable, trade		(752,000)
Intercompany payable	(671,207,000)	(473,535,000)
Total current liabilities	(671,207,000)	(474,287,000)
Long-term intercompany payable	(139,790,000)	(142,485,000)
Stockholders' equity	(937,484,000)	(891,332,000)
Total liabilities and stockholders' equity	$ (1,748,481,000)	$ (1,508,104,000)