Employee Retirement Plans (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Accumulated Benefit Obligations	$ 445.3	$ 473.8
Projected Benefit Obligations:
Beginning of year	473.9	392.1
Service cost	0.5	0.5	$ 1.1
Interest	20.0	20.2	18.5
Benefits paid	(17.3)	(16.4)
Actuarial (gain)/loss	(31.8)	77.6
Curtailment	0.0	(0.1)
End of year	445.3	473.9	392.1
Plans' Assets:
Beginning of year	434.5	399.2
Actual return on assets	(10.6)	36.7
Employer contributions	16.2	15.0
Benefits paid	(17.3)	(16.4)
End of year	422.8	434.5	$ 399.2
Consolidated Balance Sheet Components:
Net funded status	$ (22.5)	$ (39.4)
Percent of projected benefit obligations funded	94.90%	91.70%
Other assets
Consolidated Balance Sheet Components:
Defined Benefit Plan, Amounts Recognized in Balance Sheet	$ 3.5	$ 1.2
Accrued liabilities
Consolidated Balance Sheet Components:
Defined Benefit Plan, Amounts Recognized in Balance Sheet	$ (26.0)	$ (40.4)