Acquisition and Other Investments (Schedule of Business Acquisition Finite Lived Intangibles) (Details) (USD $) In Millions, unless otherwise specified					1 Months Ended		1 Months Ended		1 Months Ended		1 Months Ended
	Jun. 30, 2013		Dec. 31, 2012		May 31, 2013 Big Country [Member]	May 02, 2013 Big Country [Member]	May 31, 2013 Big Country [Member] Backlog [Member]	May 02, 2013 Big Country [Member] Backlog [Member]	May 31, 2013 Big Country [Member] Noncompete Agreements [Member]	May 02, 2013 Big Country [Member] Noncompete Agreements [Member]	May 31, 2013 Big Country [Member] Customer Relationships [Member]	May 02, 2013 Big Country [Member] Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets								$ 1.8		$ 1.8		$ 6.5
Finite-lived intangible asset, useful life					5 years		1 year		8 years		6 years
Finite-lived intangible assets, gross	$ 141.2	[1]	$ 129.4	[1]		$ 10.1

[1] Consists principally of customer relationships, backlog, trade names and non-compete agreements with finite lives.