FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Financial instruments carried at fair value

Financial assets and liabilities carried at fair value as of June 30, 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	$	266,816	$	—	$	266,816
Foreign government securities	—		211,690		211,690
U.S. government securities	—		341,981		341,981
Commercial paper	—		109,384		109,384
Short-term investments:
Foreign government securities	—		199,461		199,461
U.S. government securities	—		587,863		587,863
Corporate debt securities	—		511,803		511,803
Foreign exchange derivatives	—		369		369
Long-term investments:
Foreign government securities	—		427,511		427,511
U.S. government securities	—		735,160		735,160
Corporate debt securities	—		3,934,052		3,934,052
U.S. government agency securities	—		2,018		2,018
U.S. municipal securities	—		1,104		1,104
Ctrip convertible debt securities	—		760,399		760,399
Ctrip equity securities	535,224		—		535,224
Total assets at fair value	$	802,040	$	7,822,795	$	8,624,835

	Level 1		Level 2		Total
LIABILITIES:
Foreign exchange derivatives	$	—	$	552	$	552

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 convertible 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