Revolving Credit Facility (Details) (USD $)		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Revolving Credit Facility [Member]	Dec. 31, 2012 Revolving Credit Facility [Member]	Jan. 06, 2014 Revolving Credit Facility [Member] Subsequent Event [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] LIBOR [Member]
Line of Credit Facility [Line Items]
Credit facility maximum borrowings		$ 30,000,000.0
Standby letter of credit		900,000		800,000
Borrowings available under the revolving credit facility		29,100,000
Frequency of periodic payments		monthly
Stated percentage					2.50%
Fees associated with unused portion of committed amount		0
Borrowings outstanding under revolving credit facility		0	0
Weighted average interest rate		2.70%	2.80%
Actual net worth for compliance	164,100,000
Minimum net worth required for compliance	95,000,000
Ratio of total liability to net worth	0.3
Maximum ratio of total liability to net worth for compliance	2
Actual working capital for compliance	77,300,000
Minimum working capital for compliance	$ 40,000,000