Investments (Tables)

3 Months Ended

Mar. 31, 2017

Investments Debt And Equity Securities [Abstract]

Schedule of Fair Value of Available-for-Sale Investments by Type of Security

As of March 31, 2017 and December 31, 2016, the fair value of available-for-sale investments by type of security was as follows:

	March 31, 2017
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Investments:
Commercial Paper	$	24,151	$	31		—		$	24,182
Certificates of Deposit		10,382		—		—			10,382
Corporate Bonds		76,787		—		(103	)		76,684
Government Securities		33,005		—		(65	)		32,940
Treasury Bonds		16,098		—		(13	)		16,085
	$	160,423	$	31	$	(181	)	$	160,273

	December 31, 2016
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Investments:
Commercial Paper	$	19,631	$	58	$	—		$	19,689
Certificates of Deposit		10,629		—		—			10,629
Corporate Bonds		94,764		—		(155	)		94,609
Government Securities		33,513		—		(47	)		33,466
Treasury Bonds		17,066		1		(4	)		17,063
	$	175,603	$	59	$	(206	)	$	175,456