Benefit Plans - Defined Benefit Plans - Components of Pension Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Supplemental Retirement Plan
Components of Net Periodic Benefit Cost
Service cost	$ 862	$ 714
Interest cost	883	911
Amortization of net actuarial loss	386	142
Net periodic benefit cost	2,131	1,767
Split-Dollar Life Insurance Benefit Plan
Components of Net Periodic Benefit Cost
Amortization of prior transition obligation	(113)	(102)
Interest cost	169	196
Net periodic benefit cost	$ 56	$ 94