(CNN)Longtime Democratic Sen. Dianne Feinstein's husband, Richard Blum, died Sunday evening following "a long battle with cancer," according to an announcement from Feinstein's office.

       Feinstein, a California Democrat, said in a statement that her "heart is broken today."

       "My husband was my partner and best friend for more than 40 years," she said. "He was by my side for the good times and for the challenges. I am going to miss him terribly."

       Blum died at the family's home, the announcement from the senator's office said. He was 86. Feinstein is 88 years old.

       Senate Majority Leader Chuck Schumer, a New York Democrat, paid tribute to Blum and expressed condolences for Feinstein's loss in a Senate floor speech on Monday.

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       Schumer called Blum a friend and adviser to "so many of us."

       "In his 86 years, Dick truly led a remarkable life. He was a force of nature, gifted with a winning smile, and keen intellect that he applied to the benefit of California, America and even international causes, including the American Himalayan Foundation because he cared so much about those folks," he said.

       Schumer recalled how Blum would call him "every now and then," with his "insightful, often brilliant ideas."

       "The only problem was his enthusiasm was so intense, it was sometimes hard to get him off the phone," he said.

       "He was a strong and wonderful partner to Senator Feinstein," Schumer said of Blum. "He fought valiantly against illness in the final chapters of his life, a life so well lived."

       CNN's Ali Zaslav contributed to this report.