We classify all of our short-term investments as available-for-sale. We carry these at fair value and report unrealized gains and losses, net of taxes, in Accumulated other comprehensive loss, which is a separate component of shareholders’ equity in our Condensed Consolidated Balance Sheets. These unrealized gains and losses are also reflected in our Condensed Consolidated Statements of Comprehensive Income and Condensed Consolidated Statements of Shareholders’ Equity. We determine cost, gains, and losses using the specific identification method.

	Cost Basis		Unrealized Gains		Unrealized Losses		Fair Value
	(Thousands of dollars)
Investments:
Money market mutual funds	$	88,217	$	—	$	—	$	88,217
Deferred compensation plan assets included in other assets		889		—		—		889
Total	$	89,106	$	—	$	—	$	89,106

	Cost Basis		Unrealized Gains		Unrealized Losses		Fair Value
	(Thousands of dollars)
Investments:
Money market mutual funds	$	26,308	$	—	$	—	$	26,308
Deferred compensation plan assets included in other assets		772		—		—		772
Total	$	27,080	$	—	$	—	$	27,080

At June 30, 2019 and December 31, 2018, we classified $12.1 million of our aggregate investments as long-term investments and recorded them in our Condensed Consolidated Balance Sheets as restricted cash and investments, as they are securing outstanding letters of credit with maturities beyond one year.