v2.4.0.8
Short-Term And Long-Term Investments And Restricted Deposits (Short-Term And Long-Term Investments And Restricted Deposits By Investment Type) (Details) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2014
Dec. 31, 2013
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost $ 1,375,036 $ 945,129
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 5,439 4,788
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments (5,494) (8,945)
Fair Value 1,374,981 940,972
U.S. Treasury Securities And Obligations Of U.S. Government Corporations And Agencies [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 329,439 246,085
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 246 245
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments (4,273) (7,494)
Fair Value 325,412 238,836
Corporate Securities [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 489,304 293,912
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 2,815 2,782
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments (990) (608)
Fair Value 491,129 296,086
Restricted Certificates Of Deposit [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 5,892 5,891
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 0 0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments 0 0
Fair Value 5,892 5,891
Restricted Cash Equivalents [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 78,995 26,642
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 0 0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments 0 0
Fair Value 78,995 26,642
Municipal Securities, General Obligation [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 49,467 54,003
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 422 555
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments (14) (136)
Fair Value 49,875 54,422
Municipal Securities, Pre-Refunded [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 4,955 10,835
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 46 82
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments (16) 0
Fair Value 4,985 10,917
Municipal Securities, Revenue [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 100,312 68,801
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 768 545
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments (58) (292)
Fair Value 101,022 69,054
Municipal Securities, Variable Rate Demand Notes [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 11,700 28,575
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 0 0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments 0 0
Fair Value 11,700 28,575
Asset Backed Securities [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 185,270 138,803
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 389 579
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments (143) (332)
Fair Value 185,516 139,050
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 46,023 33,974
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 753 0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments 0 (83)
Fair Value 46,776 33,891
Cost And Equity Method Investments [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 58,051 22,239
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 0 0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments 0 0
Fair Value 58,051 22,239
Life Insurance Contracts [Member]
    
Schedule Of Investments And Restricted Deposits By Type [Line Items]    
Amortized Cost 15,628 15,369
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments 0 0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments 0 0
Fair Value $ 15,628 $ 15,369