Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Defined pension plan benefits
Components of net periodic benefit cost
Service cost – benefits earned during the year	$ 7	$ 16
Interest cost on projected benefit obligations	455	446
Expected return on plan assets	(549)	(543)
Amortization of prior service (benefit) cost	0	0
Amortization of net loss	157	191
Net periodic benefit cost	70	110
Other postretirement benefits
Components of net periodic benefit cost
Service cost – benefits earned during the year	36	40
Interest cost on projected benefit obligations	64	66
Expected return on plan assets	0	0
Amortization of prior service (benefit) cost	(6)	13
Amortization of net loss	0	0
Net periodic benefit cost	$ 94	$ 119