Investments (Tables)

3 Months Ended

Mar. 31, 2015

Investments Debt And Equity Securities [Abstract]

Investment Balances

Investment balances are presented in the table below (in thousands). All investments are carried at fair value and are accounted for as trading securities.

			Gross		Gross			Estimated
			Unrealized		Unrealized			Market
	Cost		Gains		Losses			Value
March 31, 2015:
U.S. Government and Government agency obligations	$	30,293	$	17	$	(1	)	$	30,309
Money market funds		26,332		—		—			26,332
Equity funds		7,163		279		(44	)		7,398
Marketable securities	$	63,788	$	296	$	(45	)	$	64,039
December 31, 2014:
U.S. Government and Government agency obligations	$	66,761	$	20	$	(8	)	$	66,773
Money market funds		8,250		—		—			8,250
Equity funds		4,477		223		(103	)		4,597
Marketable securities	$	79,488	$	243	$	(111	)	$	79,620