Pension and Other Post-Retirement Benefit Plans (Cash Flows) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 24,731,000	$ 17,991,000
Estimated future employer contributions	27,700,000
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2013	28,810,000
2014	32,901,000
2015	32,166,000
2016	34,639,000
2017	36,711,000
Years 2018 to 2022	217,159,000
Post-Retirement Healthcare Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	974,000	1,304,000
Estimated future employer contributions	1,100,000
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2013	1,105,000
2014	1,009,000
2015	922,000
2016	841,000
2017	823,000
Years 2018 to 2022	$ 3,944,000