With steady growth over the past four years, nonbank mortgage servicers should have more regulatory oversight, according to a recently released study by the U.S. Government Accountability Office. Several agencies, including the Conference of State Bank Supervisors and the Federal Housing Finance Agency, agreed with that recommendation. The share of home mortgages serviced by nonbanks tripled from 2012 to midyear 2015, growing from approximately 6.8 percent to 24.2 percent, the GAO said. The GAO recommended...