185 The following table breaks down bonds in Aegon USA’s portfolio that are insured by monoline insurers. The disclosure by rating follows  a hierarchy of S&P, Moody’s, Fitch, Internal and NAIC. The rating that is provided by the rating agencies on these guaranteed bonds is the higher of the guarantor’s rating or the rating of  the underlying bond itself.  Of the EUR 751 million (2012: EUR 892 million) indirect exposure on the monoline insurers, 34% relates to MBIA, 28% to AMBAC, 7%  to FGIC and 24% to FSA (2012: 34% related to MBIA, 27% to AMBAC, 7% to FGIC and 24% to FSA).  At the end of 2013, Aegon USA had no indirect exposure via wrapped bonds via holdings in monoline insurers and derivative  counterparty exposure where monoline insurers are Aegon's counterparty (2012: no indirect exposure). The amortized cost and fair value of debt securities, money market investments and other, included in Aegon’s available-for-sale (AFS)  portfolios, are as follows as of December 31: Additional information on credit risk, unrealized losses and impairments Debt instruments 2013 Amortized  cost Unrealized  gains Unrealized  losses Total fair  value Fair value of  instruments  with  unrealized  gains Fair value of  instruments  with  unrealized  losses Debt securities United States Government 5,538 241 (257) 5,522 2,621 2,901 Dutch Government 3,705 144 (25) 3,824 3,441 383 Other Government 12,766 738 (232) 13,272 9,317 3,954 Mortgage backed securities 9,433 613 (246) 9,800 6,886 2,914 Asset backed securities 6,780 401 (162) 7,019 4,171 2,848 Corporate 45,851 3,586 (712) 48,725 38,576 10,149 Money market investments 5,524 - - 5,524 5,524 - Other 1,042 148 (28) 1,163 1,002 160 Total 90,638 5,873 (1,662) 94,849 71,539 23,310 Of which held by Aegon Americas, NL and UK 87,900 5,728 (1,603) 92,026 69,573 22,453 2013 2012 Bonds insured by monoline insurers Amortized  cost Fair value Amortized  cost Fair value AAA 46 48 53 57 AA 178 174 224 208 < AA 527 503 615 541 At December 31 751 725 892 806