Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents		$ 368,518	$ 260,149
Short-term investments, available-for-sale		502,852	529,260
Accounts receivable, net of allowances of $7,719 and $5,976 at December 31, 2015 and 2014, respectively		669,276	674,401
Inventories, net		10,521	12,617
Prepaid expenses and other current assets		132,784	166,005
Current portion of deferred tax assets, net	[1]	0	45,892
Total current assets		1,683,951	1,688,324
Long-term investments, available-for-sale		891,964	1,073,110
Property and equipment, net		373,817	367,779
Goodwill		1,962,722	1,796,851
Other intangible assets, net		283,418	390,717
Long-term portion of deferred tax assets, net		215,196	128,198
Other assets		70,370	67,028
Total assets		5,481,438	5,512,007
Current liabilities:
Accounts payable		95,396	79,884
Accrued expenses and other current liabilities		317,468	298,079
Income taxes payable		18,351	12,053
Current portion of deferred revenues		1,249,754	1,200,093
Total current liabilities		1,680,969	1,590,109
Long-term portion of deferred revenues		414,314	357,771
Convertible notes		1,324,992	1,292,953
Other liabilities		$ 87,717	$ 97,529
Commitments and contingencies
Preferred stock at $.01 par value: 5,000 shares authorized, none issued and outstanding		$ 0	$ 0
Common stock at $.001 par value: 1,000,000 shares authorized; 299,113 and 294,674 shares issued and outstanding at December 31, 2015 and 2014, respectively		299	295
Additional paid-in capital		4,566,919	4,292,706
Retained earnings		3,474,625	3,155,264
Accumulated other comprehensive loss		(28,527)	(36,790)
Stockholders' equity before treasury stock		8,013,316	7,411,475
Less - common stock in treasury, at cost (145,296 and 133,898 shares at December 31, 2015 and 2014, respectively)		(6,039,870)	(5,237,830)
Total stockholders' equity		1,973,446	2,173,645
Total liabilities and stockholders' equity		$ 5,481,438	$ 5,512,007

[1] During the year ended December 31, 2015, the Company elected to early adopt an accounting standard update on income taxes on a prospective basis. The new authoritative guidance requires deferred tax liabilities and assets along with any related valuation allowance to be classified as noncurrent on the consolidated balance sheet. The December 31, 2014 consolidated balance sheet was not retrospectively adjusted.