5. Cash, Cash Equivalents and Available for Sale Securities

The Company considers all highly liquid investments purchased with original maturities of 90 days or less at the date of purchase to be cash equivalents. Cash and cash equivalents included cash of $5.5 million and $4.7 million at December 31, 2015 and 2014, respectively. Cash and cash equivalents at December 31, 2015 and December 31, 2014 also included $216.4 million and $35.1 million, respectively, of investments in money market funds and U.S. Treasury securities with original maturities of 90 days or less.

The Company considers securities with original maturities of greater than 90 days to be available for sale securities. The Company held available for sale securities with a fair value totaling $170.0 million and $423.7 million as of December 31, 2015 and 2014, respectively. These available for sale securities consisted of U.S. Treasury securities and investment-grade corporate debt securities. At December 31, 2015, the Company held available for sale securities of $74.7 million with maturities of less than one year, and $95.3 million with maturities of greater than one year. The Company evaluates securities with unrealized losses, if any, to determine whether such losses are other than temporary. The Company has determined that there were no other than temporary losses in fair value of its investments as of December 31, 2015. The Company classifies these securities as available for sale, however, the Company does not currently intend to sell its investments and the Company believes it is more likely than not that the Company will recover the carrying value of these investments.

Available for sale securities, including carrying value and estimated fair values, are summarized as follows:

	As of December 31, 2015
	Cost		Fair Value		Carrying Value		Unrealized Loss
U.S. Treasury securities	$	130,507	$	130,196	$	130,196	$	(311	)
Corporate debt securities		39,995		39,833		39,833		(162	)

Total	$	170,502	$	170,029	$	170,029	$	(473	)

	As of December 31, 2014
	Cost		Fair Value		Carrying Value		Unrealized Loss
U.S. Treasury securities	$	423,859	$	423,746	$	423,746	$	(113	)
Corporate debt securities		—		—		—		—

Total	$	423,859	$	423,746	$	423,746	$	(113	)

The Company's available for sale securities are reported at fair value on the Company's balance sheet. Unrealized gains (losses) are reported within accumulated other comprehensive income (loss) in the statements of comprehensive income (loss). The cost of securities sold and any realized gains/losses from the sale of available for sale securities are based on the specific identification method. The changes in accumulated other comprehensive income (loss) associated with the unrealized loss on available for sale securities for the years ended December 31, 2015 and December 31, 2014 were as follows:

	Years ended December 31,
	2015			2014
Beginning balance	$	(65	)	$	—
Current period changes in fair value before reclassifications, net of tax		(351	)		(65	)
Amounts reclassified from accumulated other comprehensive income, net of tax		(57	)		—

Total other comprehensive income, net of tax		(408	)		(65	)

Ending balance	$	(473	)	$	(65	)