SEGMENT INFORMATION - Schedule of Segment Revenues from Major Customers (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Revenue, Major Customer [Line Items]
Revenue from contracts with customers	$ 275,100	$ 356,982
PAMC
Revenue, Major Customer [Line Items]
Revenue from contracts with customers	258,599	339,164
Revenue \| Customer Concentration Risk \| Customer A \| PAMC
Revenue, Major Customer [Line Items]
Revenue from contracts with customers	38,908	61,872
Revenue \| Customer Concentration Risk \| Customer B \| PAMC
Revenue, Major Customer [Line Items]
Revenue from contracts with customers	104,354	123,118
Revenue \| Customer Concentration Risk \| Customer C \| PAMC
Revenue, Major Customer [Line Items]
Revenue from contracts with customers	$ 35,683	$ 41,866

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

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