FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2015

Fair Value Disclosures [Abstract]

Financial instruments carried at fair value

Financial assets and liabilities carried at fair value as of March 31, 2015 are classified in the tables below in the categories described below (in thousands): 

	Level 1		Level 2		Total
ASSETS:
Cash equivalents:
Money market funds	$	286,477	$	—	$	286,477
Foreign government securities	—		386,404		386,404
U.S. government securities	—		1,241,506		1,241,506
Commercial paper	—		221,735		221,735
Short-term investments:
Foreign government securities	—		141,266		141,266
U.S. government securities	—		655,744		655,744
Corporate debt securities	—		545,810		545,810
Commercial paper	—		32,198		32,198
U.S. government agency securities	—		4,623		4,623
Foreign exchange derivatives	—		374		374
Long-term investments:
Foreign government securities	—		311,254		311,254
U.S. government securities	—		701,517		701,517
Corporate debt securities	—		3,042,667		3,042,667
U.S. government agency securities	—		2,546		2,546
U.S. municipal securities	—		1,107		1,107
Ctrip corporate debt securities	—		482,512		482,512
Ctrip equity securities	432,041		—		432,041
Total assets at fair value	$	718,518	$	7,771,263	$	8,489,781

	Level 1		Level 2		Total
LIABILITIES:
Foreign exchange derivatives	$	—	$	493	$	493

Financial assets and liabilities carried at fair value as of December 31, 2014 are classified in the tables below in the categories described below (in thousands):

	Level 1		Level 2		Total
ASSETS:
Cash equivalents:
Money market funds	$	155,608	$	—	$	155,608
Foreign government securities	—		974,855		974,855
U.S. government securities	—		676,503		676,503
Corporate debt securities	—		45,340		45,340
Commercial paper	—		382,544		382,544
U.S. government agency securities	—		10,000		10,000
Short-term investments:
Foreign government securities	—		52,490		52,490
U.S. government securities	—		364,266		364,266
Corporate debt securities	—		581,523		581,523
Commercial paper	—		39,092		39,092
U.S. government agency securities	—		104,811		104,811
Foreign exchange derivatives	—		336		336
Long-term investments:
Foreign government securities	—		12,671		12,671
U.S. government securities	—		556,448		556,448
Corporate debt securities	—		2,329,033		2,329,033
U.S. government agency securities	—		95,094		95,094
U.S. municipal securities	—		1,102		1,102
Ctrip corporate debt securities	—		425,961		425,961
Ctrip equity securities	335,344		—		335,344
Total assets at fair value	$	490,952	$	6,652,069	$	7,143,021

	Level 1		Level 2		Total
LIABILITIES:
Foreign exchange derivatives	$	—	$	129	$	129