INVESTMENTS

The Company classifies the marketable securities in which it invests as available-for-sale securities. These securities are measured at fair value in the financial statements with unrealized gains or losses recorded in Other comprehensive income in the Company's Consolidated Statements of Comprehensive (Loss) Income. At the time the securities are sold or otherwise disposed of, gross realized gains and losses are included in Net (loss) income. Gross realized gains and losses are based on the carrying value (cost, net of discounts or premiums) of the sold investment. The amounts reclassified out of Other comprehensive income during the nine-month periods ended September 30, 2015 and 2014, were insignificant. All of the marketable securities amounts are available to satisfy current obligations.

The amortized cost, gross unrealized gains, gross unrealized losses, and fair value of available-for-sale investment securities by major security type and class of security at September 30, 2015, and December 31, 2014 were as follows:



		Investments
(In thousands)		Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
2015
	Federal agency notes	$	286,220	$	106	$	(34	)	$	286,292
	Commercial paper	40,097		—		(45		)	40,052
	Mutual funds	419		205		—			624
	Total	$	326,736	$	311	$	(79	)	$	326,968

2014
	Federal agency notes	$	143,132	$	40	$	(33	)	$	143,139
	Commercial paper	108,371		1		(257		)	108,115
	Mutual funds	344		279		—			623
	Total	$	251,847	$	320	$	(290	)	$	251,877

The mutual funds included in the investment table above are included in Other noncurrent assets on the Company's Consolidated Balance Sheets.

The maturities of available-for-sale securities at September 30, 2015 were as follows:



(In thousands)	Amortized cost		Fair value
Federal agency notes
Due in one year or less	$	237,658	$	237,764
Due after one year through two years	48,562		48,528
Total	$	286,220	$	286,292

Commercial paper
Due in one year or less	$	26,612	$	26,567
Due after one year through two years	13,485		13,485
Total	$	40,097	$	40,052

The Company has long-term investments in several Canadian junior exploration companies, recorded on the Company's Consolidated Balance Sheets at cost. The Company determined that certain of its long-term investments were other than temporarily impaired and recorded a loss of approximately $0.2 million for the three- and nine-month periods ended September 30, 2015 and 2014. These long-term investments totaled approximately $0.7 million at September 30, 2015 and $0.9 million at December 31, 2014, and are recorded in Other noncurrent assets on the Company's Consolidated Balance Sheets.