Acquisitions (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended			36 Months Ended
	Dec. 29, 2012	Mar. 31, 2013 acquisition	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2013
Business Combinations [Abstract]
Number of businesses acquired		0
Joint venture investment loss	$ 2,670	$ 2,670	$ 0	$ 0
Current period acquisitions		3	14,084		20,768
Goodwill, expected tax deductible amount		$ 10,864			$ 10,864
Goodwill, expected tax deductible period		15 years