Debt (Details) (USD $)	9 Months Ended
	Sep. 30, 2012
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 100,000,000
Maximum borrowing capacity including accordion	125,000,000
Interest expense incurred	800,000
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	20,000,000
Swing Line of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 5,000,000