Restatement and Revision of Previously Issued Consolidated Financial Statements (Details) (USD $)	12 Months Ended														12 Months Ended
	Mar. 31, 2014 item	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2014 Maximum item	Mar. 31, 2014 Minimum item	Mar. 31, 2013 Restatement adjustment	Mar. 31, 2012 Restatement adjustment	Mar. 31, 2014 Proforma item	Mar. 31, 2012 Inventory Valuation Reserve Restatement adjustment	Mar. 31, 2011 Inventory Valuation Reserve Restatement adjustment	Mar. 31, 2011 Property Plant and Equipment Capitalization Threshold Convention	Mar. 31, 2013 Property Plant and Equipment Capitalization Threshold Convention Restatement adjustment	Mar. 31, 2012 Property Plant and Equipment Capitalization Threshold Convention Restatement adjustment	Mar. 31, 2012 Settlement Accrual	Mar. 31, 2012 Settlement Accrual Restatement adjustment	Mar. 31, 2011 Settlement Accrual Restatement adjustment
Cost of goods sold	$ 1,400,844,000	$ 1,389,643,000	$ 1,508,670,000						$ (30,700,000)	$ 30,700,000		$ 408,000	$ (25,000)
Inventory valuation reserves and supplier liability										30,700,000
Net income	74,304,000	(227,518,000)	104,237,000						30,700,000	(30,700,000)	(8,300,000)	(1,342,000)	82,000
Net income per share (in dollars per share)	$ 0.46	$ (1.44)	$ 0.60			$ (0.02)	$ 0.18		$ 0.17	$ (0.17)
Number of items on lists of financial items				50	30
Number of historical items from lists recorded in an earlier period or different amount recorded								9
Period relating to historical items from lists recorded in an earlier period or different amount recorded								5 years
Number of items on lists that were not addressed in a timely manner before correction	2
Number of items not material individually or in aggregate to any of annual or interim periods reported and not being corrected	6
Number of elements to restatement related to the revenue product	2
Retained earnings	976,292,000	966,924,000									(8,300,000)	7,034,000
Operating expense	651,883,000	961,671,000	693,535,000									1,300,000	(100,000)
Operating income (loss)	75,986,000	(252,037,000)	113,998,000									(1,300,000)	100,000		(1,300,000)	1,300,000
Legal accruals														$ 1,300,000