Defined Benefit Pension Plans Defined Benefit Pension Plan Additional Information (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer	$ 33,000	$ 40,000	$ 388,000	$ 431,000	$ 520,000
Current Fiscal Year End Date			--12-31
Estimated Future Employer Contributions in Current Fiscal Year	$ 474,000		$ 474,000