Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities
Net income	$ 497,631	$ 439,453
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	148,394	116,294
Provision for doubtful accounts	295	3,600
Amortization of debt issuance costs	1,172	1,093
Stock-based compensation expense	6,856	4,804
Loss from disposition of fixed assets	2,635	4,679
Deferred income taxes	34,459	83,443
Windfall tax benefits from share-based payment arrangements	(6,670)	(5,056)
(Income) loss from equity method investments, net of dividends	(3,199)	1,586
Other gains, net	(495)	0
Changes in operating assets and liabilities
Accounts receivable	6,055	(18,874)
Inventories	80,492	(26,325)
Prepaid expenses and other current assets	458	(5,038)
Accounts payable	(98,769)	19,518
Accrued liabilities	111,965	(15,755)
Other, net	(5,155)	(55,922)
Net cash provided by operating activities	776,124	547,500
Cash flows from investing activities
Acquisition of business, net of cash acquired	(611,087)	(178,309)
Additions to equity investments	0	(23,338)
Additions to property, plant and equipment	(311,183)	(498,290)
Construction of assets pending sale-leaseback	0	(136)
Proceeds from disposition of assets	145	78
Proceeds from repayment of loan acquired	45,923	0
Proceeds from repayment of loan to affiliate	0	167
Proceeds from sale and maturities of securities	342,045	239,764
Purchase of securities and other investments	(117,332)	(232,286)
Settlements of derivative instruments	(689)	(2,297)
Net cash used for investing activities	(652,178)	(694,647)
Cash flows from financing activities
Capitalized debt issuance costs	(1,167)
Dividends paid	(55,690)	(40,204)
Net proceeds from issuance of Westlake Chemical Partners LP common units	286,088	0
Proceeds from exercise of stock options	5,502	3,182
Repurchase of common stock for treasury	(9,495)	(19,409)
Windfall tax benefits from share-based payment arrangements	6,670	5,056
Net cash provided by financing activities	231,908	(51,375)
Effect of exchange rate changes on cash	(3,687)	0
Net increase in cash and cash equivalents	352,167	(198,522)
Cash and cash equivalents at beginning of period	461,301	790,078
Cash and cash equivalents at end of period	$ 813,468	$ 591,556