Parent Company Financial Statements (Schedule Of Condensed Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Condensed Financial Statements, Captions [Line Items]
Net Income (Loss)	$ 348,715	$ 336,752	$ 420,300
Depreciation, amortization, and accretion	144,252	28,305	31,498
Net increase in other assets	(24,163)	169,540	153,148
Net (decrease) increase in other liabilities	(94,910)	230,223	(9,376)
Net cash provided by operating activities	669,840	1,065,029	662,723
Net increase in advances to subsidiaries	274,587	0	0
Net cash received from sale of Umpqua Investments, Inc.	0	0	10,781
Net cash provided (used) in investing activities	501,736	(3,533,092)	(1,534,275)
Dividends paid on common stock	(270,261)	(182,273)	(183,734)
Repurchases and retirement of common stock	(6,282)	(4,163)	(80,690)
Net proceeds from issuance of common stock	1,185	54	34
Net cash (used) provided by financing activities	(303,685)	1,001,085	1,059,992
Net increase (decrease) in cash and cash equivalents	867,891	(1,466,978)	188,440
Cash and cash equivalents, beginning of period	1,294,643	2,761,621	2,573,181
Cash and cash equivalents, end of period	2,162,534	1,294,643	2,761,621
Umpqua Holdings Corporation
Condensed Financial Statements, Captions [Line Items]
Net Income (Loss)	348,715	336,752	420,300
Gain on sale of Umpqua Investments, Inc.	0	0	(4,444)
Equity in undistributed earnings of subsidiaries	(21,498)	(161,674)	(23,876)
Depreciation, amortization, and accretion	(228)	(228)	(228)
Net increase in other assets	(176)	(2,334)	(1,001)
Net (decrease) increase in other liabilities	(5,472)	2,212	2,589
Net cash provided by operating activities	321,341	174,728	393,340
Net increase in advances to subsidiaries	(143,535)	(121,409)	(313)
Net cash received from sale of Umpqua Investments, Inc.	0	0	10,781
Net cash provided (used) in investing activities	(143,535)	(121,409)	10,468
Net increase (decrease) in advances from subsidiaries	317	(379)	409
Dividends paid on common stock	(270,261)	(182,273)	(183,734)
Repurchases and retirement of common stock	(6,282)	(4,163)	(80,690)
Net proceeds from issuance of common stock	1,185	54	34
Net cash (used) provided by financing activities	(275,041)	(186,761)	(263,981)
Net increase (decrease) in cash and cash equivalents	(97,235)	(133,442)	139,827
Cash and cash equivalents, beginning of period	143,130	276,572	136,745
Cash and cash equivalents, end of period	$ 45,895	$ 143,130	$ 276,572