Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2012

Summary of Significant Accounting Policies [Abstract]

Fair Value Measurements

	September 30, 2012						December 31, 2011
	Level 1		Level 2		Total		Level 1		Level 2		Total
Assets:
Cash and cash equivalents:
Money market funds	$	24,996	$	—	$	24,996	$	77,174	$	—	$	77,174
Commercial paper		—		50,272		50,272		—		4,798		4,798
Short-term investments:
Commercial paper		—		19,883		19,883		—		12,097		12,097
U.S. government agency bonds		—		4,609		4,609		—		—		—
Total	$	24,996	$	74,764	$	99,760	$	77,174	$	16,895	$	94,069
Liabilities:
Interest rate swap contracts (1)	$	—	$	1,196	$	1,196	$	—	$	1,005	$	1,005
Total	$	—	$	1,196	$	1,196	$	—	$	1,005	$	1,005

(1) As of September 30, 2012 and December 31, 2011, the fair value of the interest rate swap contracts were classified on our Balance Sheet in “Other non-current liabilities”.