CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 937,858	$ 852,881
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	45,879	47,843
Gain on disposal of property and equipment	(210)	(7)
Impairment of intangibles	7,000
Stock-based compensation	53,042	46,890
Deferred income taxes		540
Effect on cash of changes in operating assets and liabilities:
Accounts receivable	(201,677)	(179,838)
Distributor receivables	341	5,813
Inventories	39,490	(44,947)
Prepaid expenses and other assets	(20,446)	(16,121)
Prepaid income taxes	11,460	6,174
Accounts payable	(9,724)	69,480
Accrued liabilities	53,501	(9,592)
Accrued promotional allowances	31,915	55,799
Accrued distributor terminations	(150)	6
Accrued compensation	(1,214)	(3,901)
Income taxes payable	17,969	10,311
Other liabilities	(562)	(631)
Deferred revenue	(15,236)	(19,631)
Net cash provided by operating activities	949,236	821,069
CASH FLOWS FROM INVESTING ACTIVITIES:
Sales of available-for-sale investments	795,858	558,128
Purchases of available-for-sale investments	(849,276)	(835,964)
Purchases of property and equipment	(42,062)	(44,392)
Proceeds from sale of property and equipment	880	810
Additions to intangibles	(19,686)	(5,478)
Increase in other assets	(26,228)	(1,289)
Net cash used in investing activities	(140,514)	(328,185)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments on debt	(2,500)	(12,841)
Issuance of common stock	65,540	85,245
Purchases of common stock held in treasury	(595,918)	(477,721)
Net cash used in financing activities	(532,878)	(405,317)
Effect of exchange rate changes on cash and cash equivalents	929	(7,463)
NET INCREASE IN CASH AND CASH EQUIVALENTS	276,773	80,104
CASH AND CASH EQUIVALENTS, beginning of period	797,957	637,513
CASH AND CASH EQUIVALENTS, end of period	1,074,730	717,617
Cash paid during the period for:
Interest	39	306
Income taxes	$ 257,563	$ 226,883