Available-for-Sale-Securities

6 Months Ended

Jun. 30, 2017

Available-for-sale Securities [Abstract]

Available-for-Sale-Securities

The following table is a summary of available-for-sale securities recorded in cash and cash equivalents or marketable securities in our Consolidated Balance Sheets (in thousands):



	June 30, 2017									December 31, 2016
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Certificate of deposits	$	1,489.6	$	—	$	—		$	1,489.6	$	—	$	—	$	—	$	—
Corporate debt securities	46,724.4		—		(57.6		)	46,666.8		—		—		—		—
Money market funds	7,188.6		0.1		—			7,188.7		4,426.8		—		—		4,426.8
Municipal debt securities	75.0		—		—			75.0		—		—		—		—
Sovereign government securities	350.4		—		(0.2		)	350.2		—		—		—		—
Total	$	55,828.0	$	0.1	$	(57.8	)	$	55,770.3	$	4,426.8	$	—	$	—	$	4,426.8

Estimated fair values of available-for-sale securities are generally based on prices obtained from commercial pricing services. The following table summarizes the classification of the available-for-sale debt securities on our Consolidated Balance Sheets (in thousands):



	June 30, 2017		December 31, 2016
Cash and cash equivalents	$	19,445.3	$	4,426.8
Marketable securities	36,325.0		—
Total	$	55,770.3	$	4,426.8

The following table summarizes our portfolio of available-for-sale debt securities by contractual maturity (in thousands):



	June 30, 2017
	Amortized Cost		Estimated Fair Value
Less than one year	$	55,828.0	$	55,770.3
Greater than one year	—		—
Total	$	55,828.0	$	55,770.3