Employee Benefit Plans (Cash Flows) (Details) (USD $)	Dec. 31, 2011
Disclosure of Expected Gross Prescription Drug Subsidy Receipts [Abstract]
Postretirement Benefits - Prescription Drug Subsidy, 2012	$ (278,000)
Postretirement Benefits - Prescription Drug Subsidy, 2013	(284,000)
Postretirement Benefits - Prescription Drug Subsidy, 2014	(289,000)
Postretirement Benefits - Prescription Drug Subsidy, 2015	(294,000)
Postretirement Benefits - Prescription Drug Subsidy, 2016	(299,000)
Postretirement Benefits - Prescription Drug Subsidy, 2017	(1,535,000)
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Anticipated required or discretionary contributions during in next fiscal year	12,800,000
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2012	23,191,000
2013	16,450,000
2014	17,937,000
2015	19,153,000
2016	20,525,000
2017	138,746,000
Postretirement Benefit Plans
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2012	4,821,000
2013	5,090,000
2014	5,264,000
2015	5,465,000
2016	5,689,000
2017	32,332,000
Nonqualified Supplemental Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Anticipated required or discretionary contributions during in next fiscal year	2,400,000
Postretirement health care and life insurance benefit plan
Defined Benefit Plan Disclosure [Line Items]
Anticipated required or discretionary contributions during in next fiscal year	$ 3,500,000