CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 7,484	$ 2,552
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,777	2,850
Loss on disposal of fixed assets	0	96
Share–based compensation expense	2,317	1,347
Deferred income tax (benefit) expense	(276)	431
Other charges	3	(2)
Changes in operating assets and liabilities:
Receivables	(8,872)	(4,652)
Inventories	7,098	2,484
Other assets	1,017	356
Accounts payable	22,557	11,308
Accrued payroll and related benefits	(6,981)	(3,308)
Deferred revenue	10,223	5,152
Income taxes	2,234	(70)
Other accrued expenses and liabilities	434	1,475
Net cash provided by operating activities	41,015	20,019
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of short term investments	(6,496)	(4,385)
Proceeds from sales of short term investments	1,937	2,214
Capital additions	(2,432)	(2,718)
Net cash used in investing activities	(6,991)	(4,889)
CASH FLOWS FROM FINANCING ACTIVITIES:
Exercise of stock options	1,803	0
Employee tax withholdings related to the vesting of equity awards	(1,330)	(2,455)
Excess tax benefits from share-based compensation	0	862
Repurchase and retirement of common stock to satisfy employee tax withholdings	(785)	0
Payment of dividends	(5,318)	(5,180)
Net cash used in financing activities	(5,630)	(6,773)
NET INCREASE IN CASH AND CASH EQUIVALENTS	28,394	8,357
CASH AND CASH EQUIVALENTS, beginning of period	9,623	6,191
CASH AND CASH EQUIVALENTS, end of period	$ 38,017	$ 14,548