Employee Benefit Plans - Defined Benefit Plans - Components of Periodic Pension Costs (Details) - USD ($)		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other changes in plan assets and benefit obligations recognized in other comprehensive loss
Amortization of prior service cost arising during the period	[1]	$ 61,000	$ 68,000	$ 68,000
Total recognized in accumulated other comprehensive income (loss)		513,000	1,400,000	(597,000)
The Bank | Cash Balance Plan
Components of net periodic benefit cost
Service cost		1,040,000	763,000	776,000
Interest cost		468,000	451,000	425,000
Expected return on plan assets		(1,043,000)	(832,000)	(748,000)
Amortization of prior service cost		(61,000)	(68,000)	(68,000)
Recognized net actuarial loss		130,000	33,000	121,000
Net periodic benefit cost		534,000	347,000	506,000
Other changes in plan assets and benefit obligations recognized in other comprehensive loss
Net loss (gain)		602,000	2,048,000	(985,000)
Prior service cost		126,000
Amortization of prior service cost arising during the period		61,000	68,000	68,000
Deferred taxes		(276,000)	(741,000)	320,000
Total recognized in accumulated other comprehensive income (loss)		513,000	1,375,000	(597,000)
Total recognized in net periodic benefit cost and other comprehensive loss (income )		$ 1,047,000	$ 1,722,000	$ (91,000)

[1] These items are included in the computation of net periodic benefit cost, which is a component of salaries and employee benefits expense on the consolidated statements of income. See Note 12, Employee Benefit Plans, for additional information.