Balance Sheet Parenthetical (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Available-for-sale Debt Securities, Amortized Cost Basis	$ 2,487,445	$ 1,893,356
Available-for-sale Equity Securities, Amortized Cost Basis	$ 500	$ 75,538
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares Authorized	485,000,000	485,000,000
Common Stock, Shares, Issued	231,825,865	224,432,465
Common Stock, Shares, Outstanding	214,265,168	206,871,768
Treasury Stock, Shares	17,560,697	17,560,697