Employee Benefit Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Schedule of net periodic benefit cost related to pension and post-retirement healthcare
Other post-employment benefit and pension expense	$ (52,460)	$ 18,157	$ (59,358)	$ 36,485
Qualified Pension Plans
Schedule of net periodic benefit cost related to pension and post-retirement healthcare
Service cost	1,823	4,075	5,169	8,150
Interest cost	3,633	3,963	7,444	7,926
Expected return on plan assets	(3,658)	(3,406)	(7,223)	(6,811)
Amortization of actuarial loss	1,886	539	3,741	1,078
Amortization of prior service cost	(863)	0	(1,207)	0
Plan Settlement	(607)	0	(607)	0
Net periodic benefit cost	3,428	5,171	8,531	10,343
Less capitalized portion	(251)	(417)	(332)	(790)
Other post-employment benefit and pension expense	3,177	4,754	8,199	9,553
Post-retirement Healthcare Plans
Schedule of net periodic benefit cost related to pension and post-retirement healthcare
Service cost	62	6,344	4,417	12,689
Interest cost	1,013	7,311	5,678	14,622
Expected return on plan assets	0	0	0	0
Amortization of actuarial loss	32,838	924	47,874	1,847
Amortization of prior service cost	(89,550)	0	(125,526)	0
Plan Settlement	0	0	0	0
Net periodic benefit cost	(55,637)	14,579	(67,557)	29,158
Less capitalized portion	0	(1,176)	0	(2,226)
Other post-employment benefit and pension expense	$ (55,637)	$ 13,403	$ (67,557)	$ 26,932