Source: George HW Bush leaves Houston hospital Monday

HOUSTON - A source familiar with the situation says former President George H.W. Bush was discharged Monday from the hospital in Houston where he's spent the last several weeks.

He was moved out of the hospital's intensive care unit just over two weeks ago. He had been listed in guarded condition while receiving treatment for what his spokesman Jim McGrath called "a stubborn fever."

Bush was first admitted for bronchitis and remained in the hospital while doctors monitored a lingering cough. He has been hospitalized in Houston since November 23.

Doctors were at several points optimistic that his release was imminent. McGrath said in December that Bush had been undergoing physical therapy in preparation for discharge.

After release from the intensive care unit, McGrath said Bush's "exchanges with doctors and nurses now include singing." He received visits from family members including his wife over the Christmas holiday, and was serenaded by the gospel-turned-country quartet of the 1970s and '80s the Oak Ridge Boys.

Oak member Joe Bonsall said of their telephone performance for the former president, "We asked what song he would like to hear and he said 'Elvira,' so we blasted some 'oom pop a mau mau's' in the direction of Houston, Texas."

Four months older than former President Jimmy Carter, the 88 year-old Bush is the oldest of the living former presidents.

- CNN's Kevin Liptak and Gregory Wallace contributed to this report