Investments

3 Months Ended

Mar. 31, 2013

Investments Debt And Equity Securities [Abstract]

Investments

3) Investments

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

	March 31, 2013		December 31, 2012
Available-for-sale investments:
Time deposits	$	—	$	52
Bankers’ acceptance drafts		93		242
U.S. treasury obligations		13,042		13,054
U.S. agency obligations		317,686		313,514
	$	330,821	$	326,862
Trading investments:
Mutual funds		813		791
	$	331,634	$	327,653

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

	March 31, 2013		December 31, 2012
Time deposits	$	53	$	—
U.S. agency obligations		10,104		12,158
	$	10,157	$	12,158

The following tables show 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 March 31, 2013:
Short-term investments:
Bankers’ acceptance drafts	$	93	$	—	$	—		$	93
U.S. treasury obligations		13,036		6		—			13,042
U.S. agency obligations		317,517		171		(2	)		317,686
	$	330,646	$	177	$	(2	)	$	330,821
Long-term investments:
Time deposits	$	53	$	—	$	—		$	53
U.S. agency obligations		10,099		5		—			10,104
	$	10,152	$	5	$	—		$	10,157

	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
As of December 31, 2012:
Short-term 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. Realized gains or losses are reflected in income and were not material for the three months ended March 31, 2013 and 2012, respectively.

The unrealized gains and losses for trading investments were immaterial for the three months ended March 31, 2013 and 2012.