MARKETABLE SECURITIES - Trading Securities (Details) - Fair Value, Inputs, Level 1 [Member] - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Dec. 31, 2016
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fair value of securities under fair value option		$ 9.6
Other Income [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Net gain (loss) under fair value option	$ 0.2

For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

Name:	us-gaap_FairValueOptionChangesInFairValueGainLoss1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration