Fair Value (Tables)

6 Months Ended

Jun. 30, 2015

Financial assets measured at fair value on a recurring basis

As of June 30, 2015 and December 31, 2014, financial assets (excluding cash balances) measured at fair value on a recurring basis as described in Note 1, "Summary of Significant Accounting Policies," are summarized as follows (in thousands):



	As of June 30, 2015						As of December 31, 2014
	Fair Value Measurement Using						Fair Value Measurement Using
	Level 1		Level 2		Total		Level 1		Level 2		Total
Assets:
Money market funds	$	258	$	—	$	258	$	733	$	—	$	733
Total cash equivalents	258		—		258		733		—		733
Commercial paper and corporate bonds	—		414,551		414,551		—		417,126		417,126
U.S. government agency debt securities	—		14,500		14,500		—		—		—
Total marketable securities	—		429,051		429,051		—		417,126		417,126
Total financial assets	$	258	$	429,051	$	429,309	$	733	$	417,126	$	417,859