PBS says a Ken Burns documentary on the Roosevelt family is in the works for 2014.

"The Roosevelts: An Intimate History" is a seven-part documentary that runs 14 hours long. It will focus on three members of the political family: President Franklin D. Roosevelt and his wife, Eleanor, and President Theodore Roosevelt.

Meryl Streep, Paul Giamatti and Edward Herrman will provide the voices of Eleanor and cousins Theodore and Franklin.

In 2013, PBS will air "Constitution USA with Peter Sagal," a road trip by the National Public Radio host to see the document in action.

PBS also announced Saturday that Viking River Cruises has extended its sponsorship of "Masterpiece," the home of shows including the hit drama "Downton Abbey." Viking will sponsor the showcase for two more years.