Pension and Other Postretirement Benefits Pension and Other Postretirement Benefits (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Fair Value Of Plan Assets By Measurement Table [Abstract]
US Large Cap Equity Pension Assets	$ 30,938	$ 36,236
US Small Mid Cap Equity Pension Assets	22,936	27,310
Non US Equity Pension Assets	29,743	33,745
Emerging Markets Equity Pension Assets	8,004	10,208
Fixed Income Pension Assets	8,824	19,121
Long Government Credit Pension Assets	59,347	18,897
High Yield Bonds Pension Assets	12,017
Emerging Market Debt Pension Assets	11,421
Real Estate Funds Pension Assets	15,992	15,317
Absolute Return Strategy Pension Assets	32,078	30,475
Real Return Strategy Pension Assets	12,932	15,475
Cash And Cash Equivalents Pension Assets	1,459	9,290
Total Pension Asset Investments Net Of Receivables And Payables	245,691	216,074
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Fair Value Of Plan Assets By Measurement Table [Abstract]
US Large Cap Equity Pension Assets	29,047	36,236
US Small Mid Cap Equity Pension Assets	21,624	0
Non US Equity Pension Assets	13,931	22,158
Emerging Markets Equity Pension Assets	8,004	10,208
Fixed Income Pension Assets	0	19,121
Long Government Credit Pension Assets	30,098	0
High Yield Bonds Pension Assets	0
Emerging Market Debt Pension Assets	11,421
Real Estate Funds Pension Assets	15,992	0
Absolute Return Strategy Pension Assets	0	0
Real Return Strategy Pension Assets	12,932	15,475
Cash And Cash Equivalents Pension Assets	0	0
Total Pension Asset Investments Net Of Receivables And Payables	143,049	103,198
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Fair Value Of Plan Assets By Measurement Table [Abstract]
US Large Cap Equity Pension Assets	1,891	0
US Small Mid Cap Equity Pension Assets	1,312	27,310
Non US Equity Pension Assets	15,812	11,587
Emerging Markets Equity Pension Assets	0	0
Fixed Income Pension Assets	8,824	0
Long Government Credit Pension Assets	29,249	18,897
High Yield Bonds Pension Assets	12,017
Emerging Market Debt Pension Assets	0
Real Estate Funds Pension Assets	0	0
Absolute Return Strategy Pension Assets	32,078	30,475
Real Return Strategy Pension Assets	0	0
Cash And Cash Equivalents Pension Assets	1,459	9,290
Total Pension Asset Investments Net Of Receivables And Payables	102,642	97,559
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Fair Value Of Plan Assets By Measurement Table [Abstract]
US Large Cap Equity Pension Assets	0	0
US Small Mid Cap Equity Pension Assets	0	0
Non US Equity Pension Assets	0	0
Emerging Markets Equity Pension Assets	0	0
Fixed Income Pension Assets	0	0
Long Government Credit Pension Assets	0	0
High Yield Bonds Pension Assets
Emerging Market Debt Pension Assets
Real Estate Funds Pension Assets	0	15,317
Absolute Return Strategy Pension Assets	0	0
Real Return Strategy Pension Assets	0	0
Cash And Cash Equivalents Pension Assets	0	0
Total Pension Asset Investments Net Of Receivables And Payables	$ 0	$ 15,317