PENSION AND POST-RETIREMENT PLANS - MULTI-EMPLOYER DEFINED CONTRIBUTION PLANS (Details) - Multi-employer defined contribution pension plans $ in Millions	12 Months Ended
Dec. 31, 2017 USD ($) plan	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Defined Contribution Plans
Number of Multiemployer Plans \| plan	6
Employer contributions \| $	$ 5.0	$ 5.3	$ 3.8

Amount of cost for defined contribution plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

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