Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 76,070	$ 69,715	$ 55,253
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization including impairment loss	8,729	11,031	11,914
Provision for doubtful accounts	1,380	1,442	939
Noncash stock compensation	3,394	2,205	2,093
Lease expense	1,068
Deferred tax benefit	(2,330)	(158)	(591)
Change in fair value of derivatives	(169)	(302)	(1,254)
Changes in:
Accounts receivable	1,124	(21,532)	(4,116)
Inventories	(5,925)	(29,341)	(28,518)
Other assets	(4,945)	(1,016)	(1,173)
Accounts payable and accrued expenses	(4,960)	25,592	5,696
Income taxes, net	3,016	5,405	(4,352)
Net cash provided by operating activities	76,452	63,041	35,891
Cash flows from investing activities:
Purchases of short-term investments	(38,958)	(10,030)	(31,874)
Proceeds from sale of short-term investments	44,814	8,859	66,981
Purchase of equipment and leasehold improvements	(5,427)	(3,956)	(3,023)
Payment for intangible assets acquired	(6,067)	(8,509)	(1,046)
Proceeds from sale of trademark			5,886
Net cash provided by (used in) investing activities	(5,638)	(13,636)	36,924
Cash flows from financing activities:
Repayment of long-term debt	(22,321)	(23,487)	(22,362)
Proceeds from exercise of options	4,458	3,406	1,963
Dividends paid	(34,579)	(26,287)	(21,192)
Dividends paid to noncontrolling interests	(9,654)	(8,706)	(6,039)
Purchase of subsidiary shares from noncontrolling interests	(6,087)	(808)
Net cash used in financing activities	(68,183)	(55,882)	(47,630)
Effect of exchange rate changes on cash	(3,350)	(8,730)	21,330
Net increase (decrease) in cash and cash equivalents	(719)	(15,207)	46,515
Cash and cash equivalents – beginning of year	193,136	208,343	161,828
Cash and cash equivalents – end of year	192,417	193,136	208,343
Cash paid for:
Interest	1,764	1,745	1,813
Income taxes	$ 26,332	$ 24,995	$ 24,337