Accounts Receivable Discount Programs (Details) (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Accounts Receivable Discount Programs [Abstract]
Receivables discounted	$ 289,529,000	$ 280,278,000
Weighted average days	319 days	313 days
Weighted average discount rate (in hundredths)	2.70%	2.90%
Amount of discount as interest expense	$ 6,914,000	$ 7,072,000