Segment Information (Summary Of Financial Information By Reportable Segment) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Segment Reporting Information [Line Items]
Interest income	$ 112,741,000	$ 114,108,000	$ 113,594,000	$ 115,642,000	$ 121,917,000	$ 126,527,000	$ 128,417,000	$ 124,892,000	$ 456,085,000		$ 501,753,000		$ 488,596,000
Interest expense	10,912,000	12,068,000	12,582,000	13,287,000	15,262,000	18,993,000	19,056,000	19,990,000	48,849,000		73,301,000		93,812,000
Net interest income	101,829,000	102,040,000	101,012,000	102,355,000	106,655,000	107,534,000	109,361,000	104,902,000	407,236,000		428,452,000		394,784,000
Provision for non-covered loan and lease losses	4,913,000	7,078,000	6,638,000	3,167,000	6,642,000	9,089,000	15,459,000	15,030,000	21,796,000		46,220,000		113,668,000
Provision for covered loan and lease losses									7,405,000		16,141,000		5,151,000
Non-interest income	46,987,000	33,679,000	28,926,000	27,237,000	18,128,000	24,778,000	19,627,000	21,585,000	136,829,000		84,118,000		75,904,000
Non-interest expense	98,046,000	86,974,000	86,936,000	87,696,000	85,339,000	86,224,000	83,207,000	84,201,000	359,652,000		338,971,000		317,738,000
Income before income taxes	42,754,000	38,740,000	34,958,000	38,760,000	32,104,000	32,579,000	26,567,000	19,988,000	155,212,000		111,238,000		34,131,000
Provision for income taxes	14,796,000	13,587,000	11,681,000	13,257,000	10,722,000	10,717,000	8,782,000	6,521,000	53,321,000		36,742,000		5,805,000
Net income	27,958,000	25,153,000	23,277,000	25,503,000	21,382,000	21,862,000	17,785,000	13,467,000	101,891,000		74,496,000		28,326,000
Preferred stock dividends													12,192,000
Dividends and undistributed earnings allocated to participating securities	183,000	170,000	162,000	167,000	103,000	105,000	86,000	62,000	682,000	[1]	356,000	[1]	67,000	[1]
Net earnings available to common shareholders	27,775,000	24,983,000	23,115,000	25,336,000	21,279,000	21,757,000	17,699,000	13,405,000	101,209,000		74,140,000		16,067,000
Total assets	11,795,443,000				11,562,858,000				11,795,443,000		11,562,858,000		11,668,710,000
Total loans and leases (covered and non-covered)	7,158,158,000				6,510,549,000				7,158,158,000		6,510,549,000		6,444,885,000
Total deposits	9,379,275,000				9,236,690,000				9,379,275,000		9,236,690,000		9,433,805,000
Community Banking [Member]
Segment Reporting Information [Line Items]
Interest income									420,622,000		474,167,000		466,054,000
Interest expense									45,240,000		68,751,000		89,622,000
Net interest income									375,382,000		405,416,000		376,432,000
Provision for non-covered loan and lease losses									21,796,000		46,220,000		113,668,000
Provision for covered loan and lease losses									7,405,000		16,141,000		5,151,000
Non-interest income									38,272,000		43,282,000		41,534,000
Non-interest expense									307,089,000		302,883,000		286,629,000
Income before income taxes									77,364,000		83,454,000		12,518,000
Provision for income taxes									22,202,000		26,023,000		(2,342,000)
Net income									55,162,000		57,431,000		14,860,000
Preferred stock dividends													12,192,000
Dividends and undistributed earnings allocated to participating securities									682,000		356,000		67,000
Net earnings available to common shareholders									54,480,000		57,075,000		2,601,000
Total assets	10,984,996,000				11,086,493,000				10,984,996,000		11,086,493,000		11,314,681,000
Total loans and leases (covered and non-covered)	6,713,792,000				6,171,368,000				6,713,792,000		6,171,368,000		6,198,532,000
Total deposits	8,968,867,000				8,830,353,000				8,968,867,000		8,830,353,000		9,160,058,000
Wealth Management [Member]
Segment Reporting Information [Line Items]
Interest income									15,192,000		13,362,000		9,978,000
Interest expense									865,000		2,067,000		1,435,000
Net interest income									14,327,000		11,295,000		8,543,000
Non-interest income									13,759,000		13,963,000		12,967,000
Non-interest expense									15,108,000		15,630,000		15,503,000
Income before income taxes									12,978,000		9,628,000		6,007,000
Provision for income taxes									5,171,000		3,457,000		1,905,000
Net income									7,807,000		6,171,000		4,102,000
Net earnings available to common shareholders									7,807,000		6,171,000		4,102,000
Total assets	90,370,000				53,044,000				90,370,000		53,044,000		37,757,000
Total loans and leases (covered and non-covered)	74,132,000				38,810,000				74,132,000		38,810,000		23,631,000
Total deposits	382,033,000				390,992,000				382,033,000		390,992,000		262,148,000
Home Lending [Member]
Segment Reporting Information [Line Items]
Interest income									20,271,000		14,224,000		12,564,000
Interest expense									2,744,000		2,483,000		2,755,000
Net interest income									17,527,000		11,741,000		9,809,000
Non-interest income									84,798,000		26,873,000		21,403,000
Non-interest expense									37,455,000		20,458,000		15,606,000
Income before income taxes									64,870,000		18,156,000		15,606,000
Provision for income taxes									25,948,000		7,262,000		6,242,000
Net income									38,922,000		10,894,000		9,364,000
Net earnings available to common shareholders									38,922,000		10,894,000		9,364,000
Total assets	720,077,000				423,321,000				720,077,000		423,321,000		316,272,000
Total loans and leases (covered and non-covered)	370,234,000				300,371,000				370,234,000		300,371,000		222,722,000
Total deposits	28,375,000				15,345,000				28,375,000		15,345,000		11,599,000
Umpqua Bank [Member]
Segment Reporting Information [Line Items]
Provision for income taxes									(4,904,000)		(4,325,000)		(1,594,000)
Net income									101,891,000		74,496,000		28,326,000
Preferred stock dividends													12,192,000
Dividends and undistributed earnings allocated to participating securities									682,000		356,000		67,000
Net earnings available to common shareholders									101,209,000		74,140,000		16,067,000
Total assets	$ 1,938,494,000				$ 1,884,335,000				$ 1,938,494,000		$ 1,884,335,000

[1] Represents dividends paid and undistributed earnings allocated to nonvested restricted stock awards.