XML 70 R76.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
PENSION AND POST-RETIREMENT PLANS - MULTI-EMPLOYER DEFINED CONTRIBUTION PLANS (Details) - Multi-employer defined contribution pension plans
$ in Millions
12 Months Ended
Dec. 31, 2019
USD ($)
plan
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Defined Contribution Plans      
Number of Multiemployer Plans | plan 6    
Employer contributions | $ $ 5.3 $ 4.8 $ 5.0