DEBT, CREDIT FACILITY, AND CAPITAL LEASE OBLIGATIONS (Debt Issuance and Redemption) (Details) - USD ($)	1 Months Ended
Dec. 31, 2018	Nov. 30, 2018
Unsecured Debt \| Notes 2018, Due June 1, 2048
Debt Instrument [Line Items]
Debt instrument, face amount		$ 300,000,000
Secured Debt \| Tax Exempt Variable Rate
Debt Instrument [Line Items]
Debt extinguishment	$ 37,000,000	$ 100,000,000

Face (par) amount of debt instrument at time of issuance.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant