Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 238,510	$ 142,608
Short-term investments	138,896	223,504
Accounts receivable, net	155,386	157,056
Inventories, net	140,408	131,995
Prepaid expenses and other current assets	32,911	38,082
Deferred income taxes, net	27,767	26,304
Total current assets	733,878	719,549
Property and equipment, net	192,944	190,148
Goodwill	130,975	130,747
Intangible assets, net	81,042	83,866
Other long-term assets	31,916	29,984
Total assets	1,170,755	1,154,294
Current liabilities:
Accounts payable	41,629	41,111
Accrued compensation	24,656	29,616
Deferred revenue	95,448	90,074
Accrued expenses and other liabilities	34,619	37,612
Other taxes payable	20,047	24,507
Total current liabilities	216,399	222,920
Deferred income taxes	43,058	43,186
Liability for uncertain tax positions	20,270	19,494
Other long-term liabilities	15,714	16,683
Total liabilities	295,441	302,283
Commitments and contingencies
Stockholders' equity:
Preferred stock: par value $0.01; 5,000,000 shares authorized; none issued and outstanding
Common stock: par value $0.01; 180,000,000 shares authorized; 121,041,331 and 120,677,143 shares issued and outstanding, respectively	1,210	1,207
Additional paid-in capital	485,989	471,830
Retained earnings	384,147	382,474
Accumulated other comprehensive income (loss)	3,968	(3,500)
Total stockholders' equity	875,314	852,011
Total liabilities and stockholders' equity	$ 1,170,755	$ 1,154,294