Employee Benefit Plans (Defined Benefit Plan - AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015
Qualified Pension Plans
Amounts recognized in accumulated other comprehensive income/(loss):
Prior service credit	$ 0	$ 40,049
Net gain arising during the period	0	8,302
Amortization of prior service credit	(863)	(2,070)
Amortization of net actuarial loss	1,570	5,311
Plan curtailment	(1,781)	(1,781)
Plan settlement	16,151	16,149
Total amount recognized in other comprehensive income/(loss)	15,077	65,960
Estimated amounts that will be amortized from accumulated other comprehensive income/(loss) in the next three months:
Prior service credit	(863)
Net actuarial loss	1,407
Total amount estimated to be amortized from accumulated other comprehensive income/(loss) in the next three months	544
Post-retirement Healthcare Plans
Amounts recognized in accumulated other comprehensive income/(loss):
Prior service credit	0	619,454
Prior service cost	0	(9,835)
Net gain arising during the period	0	27,075
Amortization of prior service credit	(89,550)	(215,076)
Amortization of net actuarial loss	32,775	80,649
Plan curtailment	0	5,409
Total amount recognized in other comprehensive income/(loss)	(56,775)	$ 507,676
Estimated amounts that will be amortized from accumulated other comprehensive income/(loss) in the next three months:
Prior service credit	(89,550)
Net actuarial loss	32,775
Total amount estimated to be amortized from accumulated other comprehensive income/(loss) in the next three months	$ (56,775)