INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Investments

The following table summarizes, by major security type, the Company's investments as of December 31, 2015 (in thousands):

	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Short-term investments:
Foreign government securities	$	395,404	$	497	$	(104	)	$	395,797
U.S. government securities	457,001		—		(507		)	456,494
Corporate debt securities	305,654		25		(419		)	305,260
Commercial paper	11,688		—		—			11,688
U.S. government agency securities	2,009		—		(2		)	2,007
Total short-term investments	$	1,171,756	$	522	$	(1,032	)	$	1,171,246
Long-term investments:
Foreign government securities	$	718,947	$	1,367	$	(683	)	$	719,631
U.S. government securities	580,155		277		(1,982		)	578,450
Corporate debt securities	4,294,282		1,273		(18,941		)	4,276,614
U.S. municipal securities	1,080		3		—			1,083
Ctrip convertible debt securities	1,250,000		158,600		(30,050		)	1,378,550
Ctrip equity securities	630,311		346,724		—			977,035
Total long-term investments	$	7,474,775	$	508,244	$	(51,656	)	$	7,931,363

The following table summarizes, by major security type, the Company's investments as of December 31, 2014 (in thousands):

	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Short-term investments:
Foreign government securities	$	52,524	$	—	$	(34	)	$	52,490
U.S. government securities	364,276		24		(34		)	364,266
Corporate debt securities	582,160		15		(652		)	581,523
Commercial paper	39,092		—		—			39,092
U.S. government agency securities	104,829		—		(18		)	104,811
Total short-term investments	$	1,142,881	$	39	$	(738	)	$	1,142,182
Long-term investments:
Foreign government securities	$	12,707	$	—	$	(36	)	$	12,671
U.S. government securities	557,130		80		(762		)	556,448
U.S. corporate debt securities	2,332,030		2,299		(5,296		)	2,329,033
U.S. government agency securities	95,108		97		(111		)	95,094
U.S. municipal securities	1,114		—		(12		)	1,102
Ctrip corporate debt securities	500,000		—		(74,039		)	425,961
Ctrip equity securities	421,930		—		(86,586		)	335,344
Total long-term investments	$	3,920,019	$	2,476	$	(166,842	)	$	3,755,653