FAIR VALUE MEASUREMENTS - Additional Information (Details) - USD ($)	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Transfer out of Level 3 measurement	$ 0	$ 0
Transfer in to Level 3 measurement	$ 0	$ 0

Amount of transfers of financial instrument classified as a liability out of level 3 of the fair value hierarchy.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersOutOfLevel3
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration