Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended	3 Months Ended		8 Months Ended	9 Months Ended
	Jan. 24, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2011	Sep. 30, 2012
Qualified Pension [Member]
Schedule of net periodic benefit cost related to pension and post-retirement healthcare
Service cost	$ 849	$ 3,649	$ 3,597	$ 8,892	$ 11,841
Interest cost	934	3,695	3,660	9,752	10,994
Expected return on plan assets	(1,089)	(3,356)	(3,894)	(9,950)	(9,887)
Amortization of prior service cost	98			0	0
Amortization of actuarial loss	283	575	0	0	1,617
Defined Benefit Plan, Settlements, Plan Assets		89	0
Plan Settlement	0			0	445
Net periodic benefit cost	1,075	4,652	3,363	8,694	15,010
Post-retirement Healthcare [Member]
Schedule of net periodic benefit cost related to pension and post-retirement healthcare
Service cost	1,167	5,923	6,935	14,118	19,491
Interest cost	1,252	5,774	7,194	15,216	18,139
Expected return on plan assets	(1)	(8)	(5)	(10)	(25)
Amortization of prior service cost	276			0	0
Amortization of actuarial loss	368	1,398	0	0	4,762
Defined Benefit Plan, Settlements, Plan Assets		0	0
Plan Settlement	0			0	0
Net periodic benefit cost	$ 3,062	$ 13,087	$ 14,124	$ 29,324	$ 42,367