Revolving Credit Facility (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Line of Credit Facility [Line Items]
Borrowings outstanding under revolving credit facility	$ 0	$ 0
Fees associated with unused portion of committed amount	0
Actual net worth for compliance	179,000,000
Minimum net worth required for compliance	95,000,000.0
Ratio of total liability to net worth	0.38
Maximum ratio of total liability to net worth for compliance	2
Actual working capital for compliance	88,500,000
Minimum working capital for compliance	40,000,000.0
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility maximum borrowings	30,000,000.0
Standby letter of credit	800,000.0
Borrowings available under the revolving credit facility	$ 29,200,000.0
Frequency of periodic payment	monthly
Weighted average interest rate	2.65%	2.70%
Revolving Credit Facility [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Stated percentage	2.50%