Defined Benefit Pension Plans Defined Benefit Pension Plan Additional Information (Details) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer	$ 394,000	$ 388,000	$ 440,000
Estimated Future Employer Contributions in Current Fiscal Year	$ 568,000