Defined Benefit Retirement Plan (Details) (USD $)	3 Months Ended
	Mar. 31, 2014 item	Mar. 31, 2013
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	$ 32,000	$ 36,000