LONG-TERM DEBT AND LEASE OBLIGATIONS - Debt Maturities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Long-term debt, including capital lease obligations
Long-term debt, including capital lease obligations	$ 15,490
2017	192
2018	1,157
2019	1,694
2020	4,321
2021	1,958
Later Years	6,168
Long-term non-cancelable operating leases
Total	1,216
2017	215
2018	182
2019	156
2020	125
2021	102
Later Years	436
Rental expense
Rental expense under operating leases	335	$ 292	$ 242
Sublease income	$ 13	$ 12	$ 9