Short-term Investments (Tables)

3 Months Ended

Mar. 31, 2017

Investments, Debt and Equity Securities [Abstract]

Held-to-maturity Securities

The following table summarizes the held-to-maturity securities at March 31, 2017 (dollars in thousands):

	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
U.S. government securities	$	34,991	$	35	$	70	$	34,956
Total short-term investments	$	34,991	$	35	$	70	$	34,956