Employee Benefit Plans (Cash Flows) (Details) (USD $)		12 Months Ended						1 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Pension Plans	Dec. 31, 2011 Pension Plans	Dec. 31, 2012 Postretirement Benefit Plans	Dec. 31, 2011 Postretirement Benefit Plans	Dec. 31, 2012 Nonqualified Supplemental Retirement Plans	Dec. 31, 2012 Postretirement health care and life insurance benefit plan	Jan. 31, 2013 Defined Benefit Plan Discretionary Contribution [Member] Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		$ 2,379,000	$ 2,275,000	$ 3,617,000	$ 3,712,000			$ 9,000,000
Anticipated required or discretionary contributions during in next fiscal year						3,800,000	1,600,000
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2013		20,354,000		4,435,000
2014		20,982,000		4,586,000
2015		21,679,000		4,754,000
2016		23,155,000		4,940,000
2017		28,139,000		5,165,000
2018-2022		166,646,000		28,565,000
Disclosure of Expected Gross Prescription Drug Subsidy Receipts [Abstract]
Postretirement Benefits - Prescription Drug Subsidy, 2013	(243,000)
Postretirement Benefits - Prescription Drug Subsidy, 2014	(248,000)
Postretirement Benefits - Prescription Drug Subsidy, 2015	(252,000)
Postretirement Benefits - Prescription Drug Subsidy, 2016	(258,000)
Postretirement Benefits - Prescription Drug Subsidy, 2017	(260,000)
Prescription Drug Subsidy Receipts, after Year Five	$ (1,333,000)