Debt with Commerical Bank (Details) (USD $)	6 Months Ended				6 Months Ended		0 Months Ended	6 Months Ended			6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Apr. 26, 2012 Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Jun. 30, 2012 Secured Syndicated Credit Facility [Member] Revolving Credit Facility [Member] Citi Bank [Member] Y	Apr. 26, 2012 Secured Syndicated Credit Facility [Member] Revolving Credit Facility [Member] Citi Bank [Member]	Apr. 26, 2012 Credit Agreement, Seventh Amendment [Member] BOA [Member]	Jun. 30, 2012 Credit Agreement, Seventh Amendment [Member] Revolving Credit Facility [Member] BOA [Member]	Jun. 30, 2012 Secured Term Loan [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member] Y	Apr. 26, 2012 Secured Term Loan [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Jun. 30, 2012 Secured Term Loan [Member] Credit Agreement, Seventh Amendment [Member] BOA [Member]	Jun. 30, 2012 Minimum [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Jun. 30, 2012 Mid-range [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Jun. 30, 2012 Maximum [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]
Line of Credit Facility [Line Items]
Debt instrument, face amount				$ 100,000,000			$ 55,000,000			$ 45,000,000
Line of Credit Facility, Term					4
Credit agreement, maximum borrowing capacity						45,000,000
Credit agreement, amortization period									4
Line of Credit Facility, Expansion						10,000,000
Description of variable interest rate basis			LIBOR
Basis spread on variable interest rate												1.50%	1.75%	2.00%
Credit agreement, amount outstanding								32,800,000
Line of credit, interest rate at period end								1.75%
Credit agreement, average amount outstanding during period								28,200,000
Credit agreement, maximum amount outstanding during period								32,800,000
Long-term Debt											45,000,000
Credit agreement, current amount outstanding											10,700,000
Current maturities, period											12 months
Effective interest rate											1.75%
Repayments of term loan	$ 600,000	$ 0					$ 45,140,000				$ 1,700,000