5)	Investments

The fair value of short-term investments with maturities or estimated lives of less than one year consists of the following:


	Years Ended December 31,
	2013		2012
Available-for-sale investments:
Time deposits	$	3,439	$	52
Bankers acceptance drafts		491		242
Commercial paper and certificates of deposit		114,984		—
Corporate obligations		18,351		—
U.S. treasury obligations		—		13,054
U.S. agency obligations		162,450		313,514

		299,715		326,862
Trading investments:
Mutual funds (1)		1,000		791

	$	300,715	$	327,653

(1)	The mutual funds are associated with the Company’s supplemental defined contribution retirement obligations.

The fair value of long-term available-for-sale investments with maturities or estimated lives of more than one year consists of the following:


	Years Ended December 31,
	2013		2012
Time deposits	$	54	$	—
U.S. agency obligations		60,351		12,158

	$	60,405	$	12,158

The following table shows the gross unrealized gains and (losses) aggregated by investment category for short-term and long-term available-for-sale investments:


	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
As of December 31, 2013:
Short-term investments:
Available-for-sale investments:
Time deposits	$	3,439	$	—	$	—		$	3,439
Bankers acceptance drafts		491		—		—			491
Commercial paper and certificates of deposit		114,973		15		(4	)		114,984
Corporate obligations		18,360		—		(9	)		18,351
U.S. agency obligations		162,430		22		(2	)		162,450

	$	299,693	$	37	$	(15	)	$	299,715

Long-term investments:
Time deposits	$	54	$	—	$	—		$	54
U.S. agency obligations		60,374		9		(32	)		60,351

	$	60,428	$	9	$	(32	)	$	60,405


	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
As of December 31, 2012:
Short-term investments:
Available-for-sale investments:
Time deposits	$	52	$	—	$	—		$	52
Bankers acceptance drafts		242		—		—			242
U.S. treasury obligations		13,045		9		—			13,054
U.S. agency obligations		313,262		258		(6	)		313,514

	$	326,601	$	267	$	(6	)	$	326,862

Long-term investments:
U.S. agency obligations	$	12,156	$	2	$	—		$	12,158

Interest income is accrued as earned. Dividend income is recognized as income on the date the stock trades “ex-dividend.” The cost of marketable securities sold is determined by the specific identification method and realized gains or losses are reflected in income and was not material in 2013, 2012 and 2011.

The unrealized gains and losses for trading investments were immaterial in 2013.