Equity Method Investments - Schedule of Equity Investments in Affiliates (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Schedule Of Equity Method Investments [Line Items]
Equity method investments		$ 185.0	$ 160.7	[1]
Mars
Schedule Of Equity Method Investments [Line Items]
Equity method investments		84.0	85.7
Bengal
Schedule Of Equity Method Investments [Line Items]
Equity method investments		75.6	$ 75.0
Poseidon
Schedule Of Equity Method Investments [Line Items]
Equity method investments	[2]	$ 25.4

[1] Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Auger and Lockport Operations.

[2] We acquired an equity interest in Poseidon on July 1, 2015. For additional information regarding this transaction, see Note 3 - Acquisitions.