Long-Term Debt (Details) (USD $)			0 Months Ended	12 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Apr. 29, 2013 Secured credit facility	Dec. 31, 2013 Secured credit facility	Dec. 31, 2014 Secured credit facility	Dec. 31, 2013 Secured credit facility Minimum	Apr. 29, 2013 Secured credit facility Minimum	Dec. 31, 2013 Secured credit facility Maximum	Apr. 29, 2013 Secured credit facility Maximum
Long-Term Debt
Maximum borrowing capacity under the credit facility			$ 50,000,000	$ 42,500,000	$ 35,000,000
Amount outstanding under the credit facility	14,820,000	19,700,000		14,820,000
Interest rate at the end of the period (as a percent)				1.67%
Reference rate			LIBOR	LIBOR
Interest rate added to the reference rate (as a percent)				1.50%		1.25%		1.75%
Remaining maximum borrowings available pursuant to the credit facility				$ 8,565,000
Interest rate added to the reference rate, if the entity entered into the negative pledge (as a percent)							1.50%		2.00%