The head of Berkshire Hathaway has donated roughly $870 million to four family-run foundations, a continuation of the philanthropy he has undertaking since 2006. (Last year, his donations to the four foundations were valued at $750 million.)

Some 1.5 million shares of Berkshire Hathaway are going to the Susan Thompson Buffett Foundation, named after his wife. The remaining shares, some 900,000, will be split among the Sherwood Foundation, the Howard G. Buffett Foundation, and NoVo Foundation, three charities run by his children.

“At Thanksgiving I have much to be thankful for… My three children are now—and this is hard for their father to believe—between 65 and 70 years of age,” wrote Buffett. “For some years, their foundations have distributed substantial sums, occasionally to the same donee. Usually, however, the three follow different paths.”

The Thanksgiving donations, Buffett added, supplement the pledges he has made for the past 17 years, which will continue until his death. (Buffett said he feels good, but “I fully realize I am playing in extra innings.”)

Buffett is the world’s ninth-richest person, according to the Bloomberg Billionaires Index, with a total net worth of $121 billion.

The Thanksgiving donations follow donations of nearly $5 billion in June. Since 2006, he has donated over $50 billion—a figure that exceeds his net worth when he began giving away his holdings 17 years ago.

Buffett has long been clear that he wants to give away his billions of dollars. In 2006, he told Fortune he had no plans to leave his entire estate to his children, saying, “A very rich person should leave his kids enough to do anything but not enough to do nothing.”

Those now Social Security–eligible children will work together to give away their father’s wealth after his passing. And they’ll need to act unanimously in doing so, he said. As for Berkshire, he said, “We have the right CEO to succeed me and the right Board of Directors as well. Both are needed.”