Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 290,010	$ 283,996
Short-term investments, available for sale	63,550	80,966
Accounts receivable, net of allowances of $11.4 and $12.9 million, respectively	129,262	135,110
Inventories	63,099	58,343
Income taxes receivable and deferred tax assets	60,409	54,034
Other current assets	27,550	20,843
Total current assets	633,880	633,292
Property and equipment, net	119,360	86,582
Goodwill	222,398	219,383
Intangible assets, net	72,333	80,244
Deferred tax assets	56,820	52,587
Other assets	3,948	2,810
Total assets	1,108,739	1,074,898
Current liabilities:
Accounts payable	70,973	63,446
Deferred proceeds from property transaction	181,981	180,216
Accrued and other liabilities	80,664	78,945
Deferred revenue	40,007	40,229
Income taxes payable and deferred tax liabilities	4,616	7,562
Total current liabilities	378,241	370,398
Imputed financing obligation	11,000
Noncurrent contingent and other liabilities	9,284	17,742
Noncurrent deferred tax liabilities	6,629	6,210
Noncurrent income taxes payable	33,807	29,755
Total liabilities	438,961	424,105
Commitments and contingencies (Note 8)
Stockholders' equity:
Preferred stock, $0.01 par value; 5,000 shares authorized; none issued and outstanding
Common stock, $0.01 par value; 150,000 shares authorized; 80,269 and 79,193 shares issued, respectively	803	792
Additional paid-in capital	787,681	764,870
Treasury stock, at cost; 33,823 and 33,045 shares, respectively	(587,413)	(569,576)
Accumulated other comprehensive income (loss)	(3,517)	269
Retained earnings	472,224	454,438
Total stockholders' equity	669,778	650,793
Total liabilities and stockholders' equity	$ 1,108,739	$ 1,074,898