Short-term Investments (Tables)

6 Months Ended

Jun. 30, 2017

Investments, Debt and Equity Securities [Abstract]

Held-to-maturity Securities

The following table summarizes the held-to-maturity securities held at June 30, 2017 (dollars in thousands):

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
As of June 30, 2017
U.S. government securities	$	21,910	$	52	$	(73	)	$	21,889
Commercial paper	6,980		—		—			6,980
Repurchase agreement	13,000		—		—			13,000
Total short-term investments	$	41,890	$	52	$	(73	)	$	41,869