Other Retirement Plans (Schedule of Multi-Employer Plan Contributions) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Multi-Employer Plans [Line Items]
Multi-employer plans, contributions	$ 8.3	$ 9.1
Multi-Employer Plans, Pension [Member]
Multi-Employer Plans [Line Items]
Multi-employer plans, contributions	7.8	8.3
Multi-employer Plans, Postretirement Benefit [Member]
Multi-Employer Plans [Line Items]
Multi-employer plans, contributions	$ 0.5	$ 0.8
Workforce Subject to Collective Bargaining Arrangements [Member] | Minimum [Member]
Multi-Employer Plans [Line Items]
Multi-employer plans, covered employees	1,098	778
Workforce Subject to Collective Bargaining Arrangements [Member] | Maximum [Member]
Multi-Employer Plans [Line Items]
Multi-employer plans, covered employees	1,308	1,149