Long-Term Debt - Additional information (Detail) (USD $)			6 Months Ended						1 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012 Promissory Notes	Jun. 23, 2011 Promissory Notes	Jun. 30, 2012 Payable on December 23, 2013 Promissory Notes	Jun. 28, 2011 LIBOR	Jun. 28, 2011 Alternate Base Rate	Jun. 28, 2011 Alternate Base Rate Federal Funds Rate	Jun. 28, 2011 Senior Secured Term Loan	Jun. 28, 2011 Revolving Credit Facility	Jun. 30, 2012 Senior Unsecured Notes	Jun. 30, 2012 Senior Unsecured Notes Semi Annual Payment, First Payment	Jun. 30, 2012 Senior Unsecured Notes Semi Annual Payment, Second Payment
Debt Outstanding [Line Items]
Unused revolving lines of credit	$ 58,425,000
Outstanding standby letters of credit	1,575,000
Weighted average interest rate on borrowings outstanding	7.67%	7.66%
Initial principal amount of the debt instrument			7,000,000						190,000,000
Senior secured revolving credit facility										60,000,000
Debt instrument, floor rate						1.25%	2.25%
Debt instrument, Basis points						4.25%	3.25%	0.50%
Minimum quarterly principal payment amounts									475,000
Quarterly principal payments starting date									Sep. 30, 2011
Debt Instrument, Maturity Date									Jun. 30, 2017	Jun. 28, 2016	Jul. 15, 2018
Senior unsecured note											200,000,000
Debt Instrument, Interest Rate, Stated Percentage			5.00%								9.75%
Senior Unsecured Notes, Frequency of Periodic Payment											Semi-annually
Senior unsecured notes, interest payable date												--01-15	--07-15
Closing date of payment			December 23
Principal amount of note paid				4,000,000
Principal amount of notes payable					$ 3,000,000
Debt instrument, maturity date			2013-12-23