Defined Benefit Retirement Plan (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 employee	Sep. 30, 2012
Defined Benefit Retirement Plan
Number of officers for whom unfunded, non-qualified, defined benefit retirement plan is sponsored			4
Number of current officers for whom unfunded, non-qualified, defined benefit retirement plan is sponsored			2
Number of retired officers for whom unfunded, non-qualified, defined benefit retirement plan is sponsored			2
Benefits vesting period			25 years
Net periodic benefits costs, which include interest cost and amortization of net losses	$ 36,000	$ 36,000	$ 107,000	$ 106,000