Employee Benefit Plans (Components of Net Periodic Pension Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension plans
Components of net periodic benefit cost
Service cost — benefits earned during the year	$ 4	$ 4	$ 5
Interest cost on projected benefit obligations	1,769	1,888	1,842
Expected return on plan assets	(2,151)	(2,806)	(2,744)
Amortization of net loss	656	606	719
Settlement expense	762	858	806
Net periodic pension cost	1,040	550	628
Other postretirement benefits
Components of net periodic benefit cost
Service cost — benefits earned during the year	147	130	154
Interest cost on projected benefit obligations	251	269	255
Net periodic pension cost	$ 451	$ 560	$ 570