Employee Benefit Plans (Net Periodic Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during the period	$ 547	$ 532	$ 523
Interest cost on projected benefit obligation	5,419	4,992	6,196
Expected return on assets	(6,076)	(7,378)	(8,518)
Settlement loss	0	3,214	0
Special termination benefit recognized	0	3,831	0
Amortization of net loss (gain)	1,855	1,083	1,075
Net expense (income)	1,745	6,274	(724)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during the period	5	8	9
Interest cost on projected benefit obligation	385	371	430
Expected return on assets	0	0	0
Settlement loss	0	0	0
Special termination benefit recognized	0	0	0
Amortization of net loss (gain)	(75)	(97)	(60)
Net expense (income)	$ 315	$ 282	$ 379