Pension Plan Narrative (Details) (Supplemental Employee Retirement Plans, Defined Benefit [Member], USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	$ (2,162,000)	$ 0	$ 0
Defined Benefit Plan, Actuarial Gain (Loss)	85,000	(1,735,000)
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Net of Tax	(2,300,000)
Defined Benefit Plan, Benefit Obligation	0	11,896,000	10,034,000
Deferred Compensation And Retirement Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation		11,900,000
General and Administrative Expense [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension expense	$ 2,800,000	$ 500,000	$ 500,000