Pension and Postretirement Plans Pension and Postretirement Assumptions (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Healthcare cost trend		6.50%		6.50%
Rate to which the cost trend is assumed to decline (ultimate trend rate)		4.50%		4.50%
Year the rates reach the ultimate trend rate		2020		2018
Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract]
Service and interest costs for current year		$ 0.2
Service and interest costs for current year		(0.1)
Postretirement benefit obligation at December 31		4.2
Postretirement benefit obligation at December 31		$ (3.8)
Pension Plan [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate		3.40%	[1]	4.20%	3.30%
Expected long-term rate of return		7.75%		7.75%	7.75%
Future compensation growth rate		0.00%		0.00%	3.00%
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate		3.40%	[2]	4.10%	3.40%
Expected long-term rate of return		0.00%		0.00%	0.00%
Future compensation growth rate		0.00%		0.00%	0.00%
Discount rate before remeasurement of pension or postretirement liability [Member] | Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	[2]				3.10%
Discount rate after remeasurement of pension or postretirement liability [Member] | Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	[2]				3.90%

[1] Discount rate used for the remeasurement of the management pension plan in May 2013 was consistent with the discount rate previously established.

[2] For the period January 1, 2013 through July 31, 2013, the date of the remeasurement, we used a 3.10% discount rate. From that date through December 31, 2013, we used a 3.90% discount rate.