. interest and penalties associated with uncertain tax positions amounted to a benefit of $ 319 million in 2013 , $ 88 million in 2012 and $ 95 million in 2011 . these amounts reflect the beneficial impacts of various tax settlements , including those discussed below . liabilities for accrued interest and penalties were $ 665 million and $ 1.2 billion as of december 31 , 2013 and 2012 , respectively