Employee Benefit Plans (Summary of Estimated Future Benefit Payments) (Details) $ in Thousands	Dec. 31, 2015 USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2017	$ 19,403
2018	21,117
2019	20,763
2020	21,209
2021	21,917
Thereafter	102,619
Total	207,028
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2017	12,300
2018	12,716
2019	13,033
2020	13,408
2021	13,763
Thereafter	64,920
Total	$ 130,140