Commitments and Contingencies Commitments and Contingencies - Long-term Purchase Commitments (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
Long-term Purchase Commitment [Line Items]
Long-term purchase commitments	$ 700.0
2016
Long-term Purchase Commitment [Line Items]
Long-term purchase commitments	164.4
2017
Long-term Purchase Commitment [Line Items]
Long-term purchase commitments	111.0
2018
Long-term Purchase Commitment [Line Items]
Long-term purchase commitments	89.9
2019
Long-term Purchase Commitment [Line Items]
Long-term purchase commitments	62.4
2020
Long-term Purchase Commitment [Line Items]
Long-term purchase commitments	52.4
Thereafter
Long-term Purchase Commitment [Line Items]
Long-term purchase commitments	$ 219.9