Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net income	$ 254,743	$ 259,822
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	86,502	67,472
Provision for doubtful accounts	(25)	228
Loss from disposition of property, plant and equipment	2,627	2,408
Gain on involuntary conversion of assets	(1,672)	0
Deferred income taxes	363	389
Changes in operating assets and liabilities
Accounts receivable—third parties	(4,541)	(4,000)
Net accounts receivable—Westlake	68,556	(87,032)
Inventories	53	451
Prepaid expenses and other current assets	(144)	267
Accounts payable	1,026	6,026
Accrued and other liabilities	5,018	7,831
Other, net	(10,590)	(76,492)
Cash flows from investing activities	401,916	177,370
Cash flows from investing activities
Additions to property, plant and equipment	(56,607)	(268,647)
Proceeds from disposition of assets	129	157
Proceeds from involuntary conversion of assets	1,672	0
Receivable under the Investment Management Agreement—Westlake	(119,000)	0
Net cash used for investing activities	(173,806)	(268,490)
Cash flows from financing activities
Net proceeds from common units offering	110,739	0
Proceeds from debt payable to Westlake	155,257	212,175
Repayment of debt payable to Westlake	(272,765)	(1,098)
Quarterly distributions to noncontrolling interest retained in OpCo by Westlake	(263,480)	(188,736)
Quarterly distributions to unitholders	(29,512)	(25,774)
Net cash used for financing activities	(299,761)	(3,433)
Net decrease in cash and cash equivalents	(71,651)	(94,553)
Cash and cash equivalents at beginning of period	88,900	169,559
Cash and cash equivalents at end of period	$ 17,249	$ 75,006