Subsequent Event	9 Months Ended
Sep. 30, 2026
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event Subsequent to September 30, 2026, on October 20, 2026, Columbia’s Board of Directors authorized a new share repurchase program for up to $1.2 billion of the Company's common stock. Future share repurchases will be made under this new program. Repurchases under this program may be executed in the open market or through privately negotiated transactions, including under Rule 10b5-1 plans. The timing and exact amount of common share repurchases, if any, will be at the discretion of senior management and subject to various factors, including, without limitation, Columbia’s capital position, financial performance, market conditions, and regulatory considerations. The repurchase program does not obligate Columbia to purchase any particular number of shares. The authorization has no expiration date, but may be suspended, terminated or modified by Columbia's Board of Directors at any time.

Subsequent Event

9 Months Ended

Sep. 30, 2026

Subsequent to September 30, 2026, on October 20, 2026, Columbia’s Board of Directors authorized a new share repurchase program for up to $1.2 billion of the Company's common stock. Future share repurchases will be made under this new program. Repurchases under this program may be executed in the open market or through privately negotiated transactions, including under Rule 10b5-1 plans. The timing and exact amount of common share repurchases, if any, will be at the discretion of senior management and subject to various factors, including, without limitation, Columbia’s capital position, financial performance, market conditions, and regulatory considerations. The repurchase program does not obligate Columbia to purchase any particular number of shares. The authorization has no expiration date, but may be suspended, terminated or modified by Columbia's Board of Directors at any time.