Goodwill and Other Intangible Assets (Core Deposit Intangibles) (Details) - Core Deposit Intangibles - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Impairment write-offs/write downs on the core deposit intangibles	$ 0	$ 0		$ 0	$ 0
Gross balance	86,099,000			86,099,000		$ 86,099,000
Accumulated amortization	(75,044,000)			(75,044,000)		(71,570,000)
Net carrying balance	$ 11,055,000			$ 11,055,000		$ 14,529,000
Desert Community Bank
Finite-Lived Intangible Assets [Line Items]
Impairment write-offs/write downs on the core deposit intangibles			$ 1,000,000.0