Pension Plan Narrative (Details) (Supplemental Employee Retirement Plans, Defined Benefit [Member], USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Other Assets	$ 0
Defined Benefit Plan Curtailment Loss			2,300,000
Defined Benefit Plan Curtailment Gain			1,100,000
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	0	0	1,209,000
Defined Benefit Plan, Benefit Obligation	11,896,000	10,034,000	9,176,000
Deferred Compensation And Retirement Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation	11,900,000	10,000,000
General and Administrative Expense [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension expense	$ 500,000	$ 500,000	$ 2,400,000