Summary of Significant Accounting Policies (Nature of Operations and Principles of Consolidation) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) location subsidiary trust	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Mar. 17, 2018 branch
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of banking locations (more than) | location	120
Net gain on sale of business	$ 0	$ 0	$ 31,470
Principles of Consolidation
Number of wholly owned subsidiaries that are statutory business trusts | trust	6
Disaggregation of Revenue [Abstract]
Number of Wholly Owned Subsidiaries | subsidiary	4
Deposit service charges and related fee income | Revenue Benchmark
Disaggregation of Revenue [Abstract]
Revenue streams, Percent of total non-interest income	29.00%
Card income | Revenue Benchmark
Disaggregation of Revenue [Abstract]
Revenue streams, Percent of total non-interest income	26.00%
Wealth management fees | Revenue Benchmark
Disaggregation of Revenue [Abstract]
Revenue streams, Percent of total non-interest income	25.00%
Desert Community Bank
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash payment in sale of branch			499,900
Net gain on sale of business			$ 31,500
California | Desert Community Bank
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of branches sold | branch				8