The tax effects of temporary differences that give rise to the significant portions of the deferred tax assets and  liabilities at the following dates were as follows:  (Dollars in thousands) 2012 2011 Deferred tax assets: Federal alternative minimum tax credit and low income housing credit carry forwards 1,929 $ 2,040 $ Loans, including allowance for loan losses 1,793 1,820 Net operating loss carry forwards  500 464 State taxes 421 389 Deferred compensation arrangements 224 246 Valuation allowance on other real estate 213 172 Investment impairments 48 507 Other, net 84 43 Total deferred tax assets 5,212 5,681  Deferred tax liabilities: Unrealized gain on investment securities available-for-sale 2,016 2,093 Premises and equipment, net of depreciation 774 812 FHLB stock dividends 482 698 Intangible assets 86 105 Investments - 5 Total deferred tax liabilities 3,358 3,713 Less valuation allowance (500) (464) Net deferred tax asset  1,354 $ 1,504 $ As of December 31, The Federal alternative minimum tax credit carry forward does not expire and totaled $1.6 million as of December  31, 2012. In addition, the Company has low income housing credit carry forwards of $340,000 which expire in varying  amounts between 2026 and 2032. The Company has Kansas corporate net operating loss carry forwards totaling $10.3  million as of December 31, 2012, which expire between 2013 and 2022. The Company has recorded a valuation allowance  against the Kansas corporate net operating loss carry forwards. The increase in the valuation allowance during 2012 is  related to additional net operating loss carry forwards generated during 2012. A valuation allowance related to the  remaining deferred tax assets has not been provided because management believes it is more likely than not that the results  of future operations will generate sufficient taxable income to realize the deferred tax assets at December 31, 2012. Retained earnings at December 31, 2012 and 2011 includes approximately $6.3 million for which no provision for  federal income tax had been made. This amount represents allocations of income to bad debt deductions in years prior to  1988 for tax purposes only. Reduction of amounts allocated for purposes other than tax bad debt losses will create income  for tax purposes only, which will be subject to the then current corporate income tax rate.  87 