v3.3.1.900
Investment Securities - Fair Value Measurements (Details) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Fair value of marketable securities    
Total $ 625,565 $ 1,150,815
Corporate Bonds    
Fair value of marketable securities    
Debt security 562,236 1,049,139
Other    
Fair value of marketable securities    
Debt security 24,465 59,971
Strategic equity securities    
Fair value of marketable securities    
Equity security 38,864 41,705
Level 3    
Fair value of marketable securities    
Fair value of investments 0 0
Fair value measurements on recurring basis    
Fair value of marketable securities    
Cash equivalents (including restricted) 840,950 437,886
Total 625,565 1,150,815
Fair value measurements on recurring basis | Corporate Bonds    
Fair value of marketable securities    
Debt security 562,236 1,049,139
Fair value measurements on recurring basis | Other    
Fair value of marketable securities    
Debt security 24,465 59,971
Fair value measurements on recurring basis | Strategic equity securities    
Fair value of marketable securities    
Equity security 38,864 41,705
Fair value measurements on recurring basis | Level 1    
Fair value of marketable securities    
Cash equivalents (including restricted) 38,771 58,108
Total 50,942 47,335
Fair value measurements on recurring basis | Level 1 | Other    
Fair value of marketable securities    
Debt security 12,078 5,630
Fair value measurements on recurring basis | Level 1 | Strategic equity securities    
Fair value of marketable securities    
Equity security 38,864 41,705
Fair value measurements on recurring basis | Level 2    
Fair value of marketable securities    
Cash equivalents (including restricted) 802,179 379,778
Total 574,623 1,103,480
Fair value measurements on recurring basis | Level 2 | Corporate Bonds    
Fair value of marketable securities    
Debt security 562,236 1,049,139
Fair value measurements on recurring basis | Level 2 | Other    
Fair value of marketable securities    
Debt security $ 12,387 $ 54,341