Senior Subordinated Notes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended												12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Repayment of debt, cash													$ 0	$ 3,000	$ 0
Interest expense	988	1,099	1,168	1,231	1,363	1,350	1,375	1,423	1,643	1,770	1,799	1,879	4,486	5,511	7,091
8% Senior Subordinated Note [Member]
Debt Instrument [Line Items]
Prepayment of senior subordinated notes														7,000
Interest rate on notes payable					3.75%									3.75%
Repayment of debt, cash														1,000
Notes payable to related parties					4,000									4,000
Interest expense													150	184	578
Bankers' Bank Term Loan [Member]
Debt Instrument [Line Items]
Notes payable to related parties					4,000									4,000
Debt instrument, face amount					$ 2,000									$ 2,000