[["balance at january 1 2012", "$ 158578"], ["increases in current period tax positions", "40620"], ["decreases in prior period measurement of tax positions", "-18205 ( 18205 )"], ["balance at december 31 2012", "$ 180993"], ["increases in current period tax positions", "27229"], ["decreases in prior period measurement of tax positions", "-30275 ( 30275 )"], ["balance at december 31 2013", "$ 177947"]]