rent expense and certain office equipment expense under lease agreements amounted to $ 136 million , $ 132 million and $ 137 million in 2015 , 2014 and 2013 , respectively . investment commitments . at december 31 , 2015 , the company had $ 179 million of various capital commitments to fund sponsored investment funds , including consolidated vies . these funds include private equity funds , real estate funds , infrastructure funds and opportunistic funds