Employee Benefit Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of net periodic benefit cost:
Termination benefit charge	$ 2,500
Pension Benefits
Components of net periodic benefit cost:
Service cost		$ 0	$ 8,329
Interest cost		816	5,325
Expected long-term return on assets		0	(4,386)	$ (5,225)
Prior service cost amortization		0	202	246
Actuarial loss amortization		737	4,995	6,919
Termination benefit charge		0	2,477	0
Settlement charge		29,767	4,082	161
Curtailment expense (gain)		0	254	(4)
Net periodic expense		31,320	18,930	11,789
Postretirement Benefits
Components of net periodic benefit cost:
Service cost		392	262
Interest cost		466	716
Expected long-term return on assets		(457)	(1,122)	(787)
Actuarial loss amortization		0	(653)	(28)
Termination benefit charge		0	0
Transition obligation amortization		0	44	229
Net periodic expense		401	(817)	445
Continuing Operations | Pension Benefits
Components of net periodic benefit cost:
Service cost		0	6,808	5,196
Interest cost		816	4,498	4,496
Continuing Operations | Postretirement Benefits
Components of net periodic benefit cost:
Service cost		392	253	386
Interest cost		$ 466	$ 661	$ 645