EMPLOYEE RETIREMENT PLANS - Pre-tax Expense (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) plan	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Pre-tax expense
Number of regional multi-employer pension plans in which the entity participates | plan	1
Pre-tax expense	$ 84	$ 68	$ 82
Defined-contribution plans
Pre-tax expense
Pre-tax expense	52	43	51
Defined-benefit pension plans
Pre-tax expense
Pre-tax expense	$ 32	$ 25	$ 31