Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net income	$ 37,333	$ 30,046
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	2,194	1,897
Amortization of debt issuance costs	30	30
Stock-based compensation	447	445
Deferred compensation	0	19
Loss on disposal of fixed assets	13	48
Deferred income taxes	11,373	(140)
Tax benefit from exercise of stock options	(3)	0
Payment of legal settlement	(32,000)	0
Effect of changes in operating assets and liabilities:
Receivables	16,387	9,847
Inventories	7,306	3,610
Prepaid expenses and other assets	1,740	1,899
Accounts payable	1,970	4,998
Other liabilities	(4,257)	3,695
Net cash provided by operating activities	42,533	56,394
Cash flows from investing activities:
Capital expenditures	(796)	(2,184)
Net cash used in investing activities	(796)	(2,184)
Cash flows from financing activities:
Principal payments on long-term debt	(990)	(990)
Tax benefit from exercise of stock options	3	0
Proceeds from exercise of stock options	61	36
Net cash used in financing activities	(926)	(954)
Effect of exchange rate changes on cash and cash equivalents	23	0
Net increase in cash and cash equivalents	40,834	53,256
Cash and cash equivalents at beginning of period	224,253	95,788
Cash and cash equivalents at end of period	$ 265,087	$ 149,044