Employee Benefit Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income from Discontinued Operations, net
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost			$ 4,000
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,307	$ 1,484	3,923
Interest cost	3,474	3,319	10,707
Expected return on plan assets	(4,030)	(4,027)	(15,258)
Amortization of prior service cost	0	13	576
Amortization of losses (gains)	2,526	3,733	6,542
Amortization of negative plan amendment	0	0	0
Net periodic benefit cost	3,277	4,522	6,490
Postretirement
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	11	402
Interest cost	42	52	537
Expected return on plan assets	0	0	0
Amortization of prior service cost	0	0	8
Amortization of losses (gains)	(13)	12	288
Amortization of negative plan amendment	0	0	(137)
Net periodic benefit cost	$ 33	$ 75	$ 1,098