Being Flynn (2012)

Nick Flynn (Paul Dano) is a young writer trying to define himself. He misses his mother, who recently died, but his father, Jonathan (Robert De Niro), has been out of his life for 18 years. When Jonathan is in danger of losing his job and apartment, he reaches out to his son. Overwhelmed, Nick nonetheless prepares to welcome his father back into his life, then Jonathan quickly disappears again. When Nick later finds the man at a homeless shelter, he must make a big decision.