SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of Impact of Topic 606 Adoption on Unaudited Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Accounts receivable	$ 80,166
Property, plant and equipment, net	1,887,759	$ 1,828,252	$ 1,795,129
Liabilities
Deferred revenue	10,778	10,088	4,000
Deferred revenue, noncurrent	38,119	35,528	12,707
Partners' Capital	932,236	1,088,644
Balances Without Adoption of Topic 606
Assets
Accounts receivable	71,768
Property, plant and equipment, net	1,852,126		1,795,129
Liabilities
Deferred revenue	4,071		4,000
Deferred revenue, noncurrent	11,133		12,707
Partners' Capital	921,898		$ 1,084,430
Accounting Standard Update 2014-09 \| Effect of Change Increase / (Decrease)
Assets
Accounts receivable	8,398
Property, plant and equipment, net	35,633	33,123
Liabilities
Deferred revenue	6,707	6,088
Deferred revenue, noncurrent	26,986	22,821
Partners' Capital	$ 10,338	$ 4,214

General and limited partners capital account.

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For an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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The carrying amount of consideration received or receivable as of the balance sheet date on potential earnings that were not recognized as revenue in conformity with GAAP, and which are expected to be recognized as such within one year or the normal operating cycle, if longer, including sales, license fees, and royalties, but excluding interest income.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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