Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Restoration Pension Plan
Defined Benefit Plan Disclosure
Reduction of plan expense		$ 0.4
Reduction in the projected benefit obligation		$ 1.1
Benefits paid	$ 1.2
Qualified Pension Plan
Defined Benefit Plan Disclosure
Contributions made	$ 4.0