Marketable Securities (Tables)

6 Months Ended

Nov. 30, 2014

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

As of November 30, 2014 and May 31, 2014, marketable securities consisted of the following (in thousands of dollars):

As of November 30, 2014	Amortized cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Available-for-sales securities
U.S. government agency obligations	$	1,825	$	—	$	(127	)	$	1,698
	$	1,825	$	—	$	(127	)	$	1,698

As of May 31, 2014	Amortized cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Available-for-sales securities
U.S. government agency obligations	$	1,825	$	—	$	(16	)	$	1,809
	$	1,825	$	—	$	(16	)	$	1,809