Accounting Policies and Basis of Presentation (Details) (USD $)	3 Months Ended		1 Months Ended
	Mar. 31, 2012	Apr. 02, 2011	Jan. 28, 2012 PS International North Carolina	Jan. 02, 2012 PS International North Carolina	Apr. 03, 2010 PS International North Carolina
Equity method investments
Percentage ownership acquired					50.00%
Ownership after increase (as a percent)			70.00%
Payment to increase ownership interest in affiliate			$ 3,660,000
Total cash paid, net of cash acquired	2,825,000		2,825,000
Increase in working capital				14,419,000
Increase in fixed assets				163,000
Increase in goodwill				2,590,000
Increase in intangible assets				621,000
Increase in other long-term assets				96,000
Increase in non-controlling interest				5,649,000
Decrease in investments in and advances to affiliates				9,415,000
Non-cash, pay-in-kind interest income and accretion of discount recognized on a note receivable from an affiliate	$ 2,818,000	$ 2,521,000