Democrat Governor Tom Vilsack is challenging Doug Gross, his republican opponent, to release details of his personal finances. For the past six years, Vilsack — who’s a lawyer — has publicly released his family’s tax returns and a list of their assets. This past April, Gross — the G-O-P candidate who’s a lawyer, too — released a tax return showing his 2001 income as about three-quarters of a million dollars. Vilsack says that’s not good enough, as questions have been raised about Gross family investments.Vilsack has questioned an investment Gross’ wife made in a hotel in Dubuque near the Dubuque casino, which Gross represented as a lobbyist. Gross campaign officials say Vilsack’s never released a detailed net worth statement, although the Governor has released details about his investments and holdings. Vilsack made his comments on Iowa Public Television.