[["balance at january 1 2011", "$ 118314"], ["increases in current period tax positions", "46961"], ["decreases in prior period measurement of tax positions", "-6697 ( 6697 )"], ["balance at december 31 2011", "158578"], ["increases in current period tax positions", "40620"], ["decreases in prior period measurement of tax positions", "-18205 ( 18205 )"], ["balance at december 31 2012", "$ 180993"]]