Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net income	$ 2,070	$ 373	$ 462
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	840	773	713
Stock-based compensation expense	31	29	25
Loss from disposition and write-off of property, plant and equipment	28	33	49
Deferred income taxes	23	146	54
Other losses, net	16	21	1
Changes in operating assets and liabilities, net of effect of business acquisitions
Accounts receivable	(528)	(161)	59
Inventories	(309)	29	112
Prepaid expenses and other current assets	(27)	2	(1)
Accounts payable	242	67	(89)
Accrued and other liabilities	239	46	(13)
Other, net	(231)	(61)	(71)
Net cash provided by operating activities	2,394	1,297	1,301
Cash flows from investing activities
Acquisition of businesses, net of cash acquired	(2,554)	0	(314)
Additions to investments in unconsolidated subsidiaries	(24)	(18)	(862)
Additions to property, plant and equipment	(658)	(525)	(787)
Return of investment from an unconsolidated subsidiary	0	44	0
Other, net	23	(10)	9
Net cash used for investing activities	(3,213)	(509)	(1,954)
Cash flows from financing activities
Debt issuance costs	(18)	(3)	(7)
Distributions to noncontrolling interests	(48)	(55)	(50)
Dividends paid	(145)	(137)	(132)
Proceeds from debt issuance and drawdown of revolver, net	1,671	1,299	784
Proceeds from issuance of Westlake Chemical Partners LP common units, net	0	0	63
Proceeds from (repayment of) short-term notes payable, net	8	(17)	2
Repayment of revolver and senior notes	0	(1,254)	0
Repurchase of common stock for treasury	(30)	(54)	(30)
Other, net	(1)	5	0
Net cash provided by (used for) financing activities	1,437	(216)	630
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(14)	15	(2)
Net increase (decrease) in cash, cash equivalents and restricted cash	604	587	(25)
Cash, cash equivalents and restricted cash at beginning of the year	1,337	750	775
Cash, cash equivalents and restricted cash at end of the year	$ 1,941	$ 1,337	$ 750