CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income	$ 24,978	$ 21,862
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	2,150	2,616
Provision for doubtful accounts	38	165
Lease expense	196
Noncash share-based compensation	955	513
Deferred tax benefit	(565)	(258)
Change in fair value of derivatives	(294)	215
Changes in:
Accounts receivable	(32,745)	(42,959)
Inventories	(6,698)	(1,178)
Other assets	1,098	(1,200)
Accounts payable and accrued expenses	(8,875)	(6,984)
Income taxes, net	5,156	6,552
Net cash used in operating activities	(14,606)	(20,656)
Cash flows from investing activities:
Purchases of short-term investments	(22,366)	(9,979)
Proceeds from sale of short-term investments	17,037
Purchases of equipment and leasehold improvements	(964)	(580)
Payment for intangible assets acquired	(53)	(1,352)
Net cash used in investing activities	(6,346)	(11,911)
Cash flows from financing activities:
Repayment of long-term debt	(5,655)	(6,140)
Proceeds from exercise of options	2,251	1,003
Dividends paid	(8,630)	(6,561)
Purchase of subsidiary shares from noncontrolling interest	(844)
Dividends paid to minority interest		(362)
Net cash used in financing activities	(12,878)	(12,060)
Effect of exchange rate changes on cash	(2,924)	5,213
Net decrease in cash and cash equivalents	(36,754)	(39,414)
Cash and cash equivalents - beginning of period	193,136	208,343
Cash and cash equivalents - end of period	156,382	168,929
Cash paid for:
Interest	301	420
Income taxes	$ 5,185	$ 5,306