Employee Benefit Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 item	Dec. 31, 2012	Dec. 31, 2011
Employee Benefit Plans
Employer expenses related to contributions to the plan	$ 1,701,000	$ 1,512,000	$ 1,449,000
Number of shares held by KSOP	497,958	484,075
Amount contributed to the senior officers' plan	205,000	146,000	75,000
Amounts included in other liabilities for senior officers' plan	3,981,000	2,954,000
Number of key officers covered under defined benefit retirement plan	4
Number of current key officers covered under defined benefit retirement plan	2
Number of retired key officers covered under defined benefit retirement plan	2
Period of service based on which benefits will vest	20 years
Accumulated benefit obligation for defined benefit retirement plan included in other liabilities	1,949,000	2,247,000
Discount rate used in determining the actuarial present value of the projected benefit obligation (as a percent)	4.72%	3.79%
Components of net periodic benefit cost:
Interest cost	90,000	83,000	86,000
Amortization of net losses	36,000	60,000	56,000
Net periodic benefit cost	126,000	143,000	142,000
Benefits expected to be paid in each year
2014	84,000
2015	84,000
2016	84,000
2017	84,000
2018	84,000
Beyond 2018	3,446,000
Total future payments	$ 3,866,000