Parent Company Financial Statements (Schedule Of Condensed Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Other assets	$ 669,029	$ 434,201
Total assets	29,235,175	28,846,809	$ 26,939,781
Other liabilities	299,012	297,782
Junior subordinated debentures, at fair value	255,217	274,812
Junior subordinated debentures, at amortized cost	88,268	88,496
Total liabilities	26,530,598	24,532,894
Shareholders' equity	2,704,577	4,313,915
Total liabilities and shareholders' equity	29,235,175	28,846,809
Umpqua Holdings Corporation
Condensed Financial Statements, Captions [Line Items]
Non-interest bearing deposits with subsidiary bank	136,745	130,368
Investments in Bank subsidiary	2,913,649	4,590,888
Investments in Nonbank subsidiaries	30,266	29,126
Other assets	523	518
Total assets	3,081,183	4,750,900
Payable to bank subsidiary	98	91
Other liabilities	33,023	73,586
Junior subordinated debentures, at fair value	255,217	274,812
Junior subordinated debentures, at amortized cost	88,268	88,496
Total liabilities	376,606	436,985
Shareholders' equity	2,704,577	4,313,915
Total liabilities and shareholders' equity	$ 3,081,183	$ 4,750,900