Dispositions and Held-for-Sale (Held-for-Sale) (Details) $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Nov. 11, 2017 banking_branch
Assets Held-For-Sale [Line Items]
Branch assets held-for-sale	$ 0	$ 91,318
Branch liability held-for-sale	$ 0	605,111
Desert Community Bank
Assets Held-For-Sale [Line Items]
Branch liability held-for-sale		605,100
Desert Community Bank | California
Assets Held-For-Sale [Line Items]
Number of branches to be sold | banking_branch			8
Loans | Desert Community Bank
Assets Held-For-Sale [Line Items]
Branch assets held-for-sale		78,100
Premises and equipment | Desert Community Bank
Assets Held-For-Sale [Line Items]
Branch assets held-for-sale		$ 8,000