CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 11,185	$ 12,958
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	3,966	5,318
Provision for doubtful accounts receivable, product returns, and inventory valuation	496	1,609
Stock compensation expense	1,872	1,974
Deferred taxes	2,475	4,729
Other	32	1,017
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in business combinations:
Change in operating assets	6,041	(1,954)
Change in operating liabilities	(6,611)	(81,133)
Net cash provided by (used in) operating activities	19,456	(55,482)
Cash flows from investing activities:
Purchases of property and equipment	(3,434)	(3,011)
Payments for intangible asset acquisition	(7,000)
Net cash used in investing activities	(10,434)	(3,011)
Cash flows from financing activities:
Proceeds from exercise of stock options and issuance of common stock	2,697	906
Net cash provided by financing activities	2,697	906
Effect of exchange rate changes on cash and cash equivalents	(508)	(41)
Net increase (decrease) in cash and cash equivalents	11,211	(57,628)
Cash and cash equivalents, beginning of period	218,787	219,605
Cash and cash equivalents, end of period	$ 229,998	$ 161,977