Defined Benefit Pension Plans Defined Benefit Pension Plan Employer Contributions Additional Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Estimated Future Employer Contributions in Next Fiscal Year	$ 426,000
Fair Value of Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer	$ 375,000	$ 436,000
Defined Benefit Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Change in Discount Rate	140 basis point