INVESTMENTS (Tables)

3 Months Ended

Mar. 31, 2012

Investments, Debt and Equity Securities [Abstract]

Short-term investments

The following table summarizes, by major security type, the Company’s short-term investments as of March 31, 2012 (in thousands): 

	Cost		Gross  Unrealized  Gains		Gross  Unrealized Losses			Fair Value
Available for sale securities
Foreign government securities	$	908,136	$	34	$	(87	)	$	908,083
U.S. government securities	1,491,837		91		(205		)	1,491,723
U.S. agency securities	26,812		10		—			26,822
Total	$	2,426,785	$	135	$	(292	)	$	2,426,628

The following table summarizes, by major security type, the Company’s short-term investments as of December 31, 2011 (in thousands): 

	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Available for sale securities
Foreign government securities	$	1,073,731	$	588	$	(133	)	$	1,074,186
U.S. government securities	922,997		353		(28		)	923,322
U.S. agency securities	26,942		9		—			26,951
U.S. corporate notes	205		163		—			368
Total	$	2,023,875	$	1,113	$	(161	)	$	2,024,827