ARLINGTON, Va., July 19, 2016 (GLOBE NEWSWIRE) -- Total pay for outside directors at the nation's largest corporations increased by a modest 3% in 2015, driven by increases in both cash and stock compensation, according to a new analysis by Willis Towers Watson (NASDAQ:WLTW), a leading global advisory, broking and solutions company. The study also found the annual cash retainer for board service reached $100,000 for the first time as companies continue to push toward a fixed approach to director pay.