Amount of contributions made to the multiemployer plan by all employers who participate in the plan. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 7
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=49170332&loc=SL14450678-114947

Name:	us-gaap_MultiemployerPlansPlanContributions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Employee Retirement Plans (Multiemployer Pension Plans) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($) plan	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Multiemployer Plans [Line Items]
Number of underfunded plans \| plan	2
Multiemployer plan contributions	$ 6.4	$ 3.2
Withdrawal obligation	42.7
Other Long-Term Liabilities [Member]
Multiemployer Plans [Line Items]
Withdrawal obligation	35.9		$ 33.4
Accrued Liabilities [Member]
Multiemployer Plans [Line Items]
Withdrawal obligation	$ 6.8		$ 10.6