Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Fair Value, LHFS less loans transferred in at LOCM	$ 688,079	$ 513,431

Fair Value, LHFS less loans transferred in at LOCM

No definition available.

Name:	umpq_FairValueLHFSLessLoansTransferredInAtLOCM
Namespace Prefix:	umpq_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant