BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - RECENT ACCOUNTING PRONOUNCEMENTS (Details) - Letter of credit - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Summary Of Significant Accounting Policies
Outstanding letter of credit	$ 1.4	$ 1.4
Cash held as security	$ 1.5	$ 1.5

Amount of assets pledged to secure a debt instrument.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Name:	us-gaap_DebtInstrumentCollateralAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant