Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2014

Fair Value Disclosures [Abstract]

Schedule of assets measured at fair value on a recurring basis

The Company’s assets that are measured at fair value on a recurring basis, at June 30, 2014 and December 31, 2013, consist of the following:

			Fair Value Measurements at Reporting Date Using
At June 30, 2014	Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Available-for-sale marketable securities:
U.S. government and government agency obligations	$	52,168	—		$	52,168
Corporate bonds	647,792		—		647,792
Municipal bonds	46,526		—		46,526
International government agency obligations	6,210		—		6,210
Certificates of deposit	7,922		—		7,922
Equity securities	6,974		$	6,974	—
	$	767,592	$	6,974	$	760,618
At December 31, 2013
Available-for-sale marketable securities:
U.S. government and government agency obligations	$	107,521	—		$	107,521
Corporate bonds	369,193		—		369,193
Commercial paper	23,944		—		23,944
Municipal bonds	36,921		—		36,921
International government agency obligations	2,008		—		2,008
Certificates of deposit	7,514		—		7,514
Equity securities	1,166		$	1,166	—
	$	548,267	$	1,166	$	547,101