Retirement Benefits Retirement Benefits (narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation		$ 59,400,000
Pension Expense	$ 9,994,000
Supplemental Benefit Agreement (SBA) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefits Paid	$ 4,600,000