CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 14,680	$ 35,207
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	11,344	15,793
Provision for doubtful accounts receivable, product returns, and inventory valuation	1,368	2,032
Stock compensation expense	5,696	6,585
Income tax benefits relating to employee stock options	(343)	0
Deferred taxes	10,567	12,347
Other	586	2,280
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in business combinations:
Change in operating assets	5,529	(5,576)
Change in operating liabilities	10,471	(79,226)
Net cash provided by (used in) operating activities	59,898	(10,558)
Cash flows from investing activities:
Purchases of property and equipment	(23,815)	(7,189)
Payments for business combinations, net of cash acquired	(44,983)	(1,252)
Payments for intangible asset acquisitions	(8,500)	0
Net cash used in investing activities	(77,298)	(8,441)
Cash flows from financing activities:
Proceeds from exercise of stock options and issuance of common stock	6,574	2,777
Income tax benefits relating to employee stock options	343	0
Net cash provided by financing activities	6,917	2,777
Effect of exchange rate changes on cash and cash equivalents	131	(220)
Net decrease in cash and cash equivalents	(10,352)	(16,442)
Cash and cash equivalents, beginning of period	218,787	219,605
Cash and cash equivalents, end of period	$ 208,435	$ 203,163