Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commitments and Contingencies Disclosure [Abstract]
Future purchase obligations under Fluids supply agreement, aggregate	$ 205.9
Future purchase obligations under Fluids supply agreement, 2014	14.3
Future purchase obligations under Fluids supply agreement, 2015	14.3
Future purchase obligations under Fluids supply agreement, 2016	14.3
Future purchase obligations under Fluids supply agreement, 2017	14.3
Future purchase obligations under Fluids supply agreement, 2018	12.4
Future purchase obligations under Fluids supply agreement, after 2018 through 2029	136.4
Purchases under Fluids supply agreement	$ 21.3	$ 17.7	$ 15.3