Long-Term Debt (Details Textual) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Write-off debt issuance costs	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 1,326,000	$ 0	$ 0	$ 1,326,000	$ 0
Credit Facility maximum borrowing capacity	117,800,000								117,800,000
Unused borrowing capacity under the revolving credit Facility	60,000,000								60,000,000
Debt Instrument, Interest Rate, Effective Percentage	5.00%								5.00%
Credit facility matures									Jun. 13, 2016
Line of credit facility future available borrowing capacity	40,000,000								40,000,000
Maximum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage									0.375%
Minimum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage									0.25%
Base Rate [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%								1.75%
Base Rate [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%								0.50%
LIBOR Rate
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	0.2117%								0.2117%
LIBOR Rate | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.75%								2.75%
LIBOR Rate | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.50%								1.50%
Term loan [Member]
Debt Instrument [Line Items]
Credit Facility maximum borrowing capacity	57,800,000								57,800,000
Term loan principal amortization rate									5.00%
Revolving credit facility [Member]
Debt Instrument [Line Items]
Credit Facility maximum borrowing capacity	60,000,000								60,000,000
Unused borrowing capacity under the revolving credit Facility	$ 60,000,000								$ 60,000,000