STOCKHOLDERS' EQUITY - Share Repurchases (Details) - USD ($) shares in Thousands	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Dec. 14, 2017
Equity, Class of Treasury Stock [Line Items]
Purchase Not to Exceed			$ 3,000,000,000
Shares	80	0
Cost	$ 24,000,000	$ 0
February 2017
Equity, Class of Treasury Stock [Line Items]
Purchase Not to Exceed	$ 2,250,000,000
Shares	0	0
Cost	$ 0	$ 0
December 2017
Equity, Class of Treasury Stock [Line Items]
Purchase Not to Exceed	$ 3,000,000,000
Shares	80	0
Cost	$ 24,000,000	$ 0

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration