Other Retirement Plans (Schedule of Contributions to Multi-Employer Plans) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Multi-Employer Plans [Line Items]
Multi-employer plan, period contributions	$ 48.2	$ 29.2	$ 20.7
Multi-Employer Plans, Pension [Member]
Multi-Employer Plans [Line Items]
Multi-employer plan, period contributions	44.6	27.9	19.5
Multi-Employer Plans, Postretirement Benefit [Member]
Multi-Employer Plans [Line Items]
Multi-employer plan, period contributions	$ 3.6	$ 1.3	$ 1.2
Workforce Subject to Collective Bargaining Arrangements [Member] | Minimum [Member]
Multi-Employer Plans [Line Items]
Entity number of employees during period	778	308	308
Workforce Subject to Collective Bargaining Arrangements [Member] | Maximum [Member]
Multi-Employer Plans [Line Items]
Entity number of employees during period	2,734	2,509	1,538