Long-term Debt (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 04, 2012
Standby Letters of Credit [Member]
Line of credit facility, maximum borrowing capacity		$ 125,000
Revolving Credit Facility [Member]
Line of credit facility, maximum borrowing capacity		175,000
Line of credit facility optional increase capacity		50,000
Revolving credit facility, interest rate description	Depending on the Company's consolidated leverage ratio (as defined in the Credit Agreement), borrowings under the new revolving credit facility will bear interest at the option of the Company of either a LIBOR rate plus a margin of between 1.50% to 2.50% per annum or a base rate plus a margin of between 0.50% to 1.50%.
Multicurrency [Member]
Line of credit facility, maximum borrowing capacity		50,000
Swingline Loans [Member]
Line of credit facility, maximum borrowing capacity		$ 10,000
Maximum [Member] | LIBOR Rate [Member] | Revolving Credit Facility [Member]
Revolving credit facility, basis spread on variable rate	2.50%
Maximum [Member] | Base Rate [Member] | Revolving Credit Facility [Member]
Revolving credit facility, basis spread on variable rate	1.50%
Minimum [Member] | LIBOR Rate [Member] | Revolving Credit Facility [Member]
Revolving credit facility, basis spread on variable rate	1.50%
Minimum [Member] | Base Rate [Member] | Revolving Credit Facility [Member]
Revolving credit facility, basis spread on variable rate	0.50%