Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2013

Fair Value Disclosures [Abstract]

Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis as of December 31 (in thousands):

	Balance as of 2013		Quoted Prices  in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	836,387	$	516,173	$	320,214	$	—
Marketable securities	129,181		30,172		99,009		—
Derivatives	1,932		—		1,932		—
	$	967,500	$	546,345	$	421,155	$	—
Liabilities:
Derivatives	$	3,925	$	—	$	3,925	$	—

	Balance as of 2012		Quoted Prices  in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	834,562	$	672,274	$	162,288	$	—
Marketable securities	154,051		18,417		135,634		—
Derivatives	317		—		317		—
	$	988,930	$	690,691	$	298,239	$	—
Liabilities:
Derivatives	$	7,920	$	—	$	7,920	$	—