Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2012

Schedule of Fair value of Cash, Cash Equivalents and Short Term investments, by Balance Sheet Grouping

Cash, cash equivalents and short-term investments consist of the following:

	June 30, 2012				December 31, 2011
	Cost		Fair Value		Cost		Fair Value
Cash and Cash Equivalents:
Cash and overnight deposits	$	498,782	$	498,782	$	445,586	$	445,586
Corporate commercial paper	804,782		805,080		791,729		791,902
Time deposits	60,683		60,683		57,041		57,041
Total cash and cash equivalents	1,364,247		1,364,545		1,294,356		1,294,529
Short-Term Investments:
Time deposits	376		376		472		472
Total	$	1,364,623	$	1,364,921	$	1,294,828	$	1,295,001