Employee Benefit Plans, Noncontributory Defined Benefit Pension Plan (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) Plan	Mar. 31, 2016 USD ($)
Employee Benefit Plans [Abstract]
Number of plans | Plan	2
Pension Plan [Member]
Components of net periodic benefit cost [Abstract]
Service cost	$ 91	$ 90
Interest cost	167	172
Expected return on plan assets	(274)	(260)
Net amortization and deferral	60	61
Net periodic benefit cost	44	$ 63
Employer contributions	$ 520