Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 363,645	$ 331,352
Short-term investments	109,718	128,478
Accounts receivable	63,394	78,534
Inventory	56,699	60,316
Prepaid expenses and other current assets	16,260	15,059
Prepaid income taxes	15,623	12,137
Deferred income taxes	10,055	10,055
Total current assets	635,394	635,931
Intangible assets, net	642,577	648,659
Property, equipment and building improvements, net	11,552	11,983
Goodwill	13,647	13,184
Debt issue costs, net	3,254	3,488
Deferred income taxes	14,051	11,786
Other assets	10,044	11,766
Total assets	1,330,519	1,336,797
Liabilities and Stockholders' Equity
Accounts payable	16,440	11,339
Contingent consideration	7,931	7,293
Accrued expenses and other current liabilities	78,014	75,983
Income taxes payable	1,476	4,036
Total current liabilities	103,861	98,651
Other non-current liabilities	1,863	1,967
Contingent consideration	14,163	12,896
Deferred tax liability, net	177,755	178,706
Long-term debt	155,464	153,453
Total liabilities	453,106	445,673
Stockholders' equity:
Preferred stock, par value $0.001 per share. 5,000,000 shares authorized; Series A convertible participating preferred stock; no shares issued and outstanding
Common stock, par value $0.002 per share. 175,000,000 shares authorized; outstanding 69,717,726 shares at March 31, 2012 and 70,568,501 shares at December 31, 2011	161	159
Treasury shares, at cost. 10,765,183 shares at March 31, 2012 and 9,159,083 shares at December 31, 2011	(219,657)	(169,661)
Additional paid-in capital	764,806	749,519
Accumulated other comprehensive loss	(2,409)	(3,414)
Retained earnings	334,512	314,521
Total stockholders' equity	877,413	891,124
Total liabilities and stockholders' equity	$ 1,330,519	$ 1,336,797