. ( 3 ) unconditional purchase obligations primarily include software licenses and long-term purchase contracts for network , communication and office maintenance services , which are unrecorded as of december 31 , 2016 . ( 4 ) the company has $ 18.4 million of unrecognized tax benefits , including estimated interest and penalties , that have been recorded as liabilities in accordance with income tax accounting guidance for which the company is uncertain as to if or when such amounts may be settled