Dispositions (Narrative) (Details) $ in Thousands		3 Months Ended
	Mar. 17, 2018 USD ($) branch	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)
Disposition [Line Items]
Net gain on sale of business		$ 0	$ 31,470
Desert Community Bank
Disposition [Line Items]
Net cash payment in sale of branches	$ 499,900
Net gain on sale of business			$ 31,500
Desert Community Bank | Deposits
Disposition [Line Items]
Branch liabilities sold	613,700
Desert Community Bank | Loans
Disposition [Line Items]
Branch assets sold	59,100
Desert Community Bank | Cash and cash equivalents
Disposition [Line Items]
Branch assets sold	9,000
Desert Community Bank | Premises and equipment
Disposition [Line Items]
Branch assets sold	$ 7,900
Desert Community Bank | California
Disposition [Line Items]
Number of branches sold | branch	8