Loans Receivable, Net - Aging of Recorded Investment in Past Due Loans Excluding PCI Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 40,618	$ 63,780
90 Days or Greater Past Due	22,197	27,126
Loans Not Past Due	7,831,919	7,692,326
Total	7,872,537	7,756,106
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	17,099	29,096
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	1,322	7,558
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	1,232	4,005
90 Days or Greater Past Due	394	327
Loans Not Past Due	497,013	466,651
Total	498,245	470,656
Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	169	3,050
Commercial and industrial | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	669	628
Commercial real estate – owner occupied
Financing Receivable, Past Due [Line Items]
Total Past Due	8,368	8,886
90 Days or Greater Past Due	7,719	7,871
Loans Not Past Due	1,057,983	1,136,179
Total	1,066,351	1,145,065
Commercial real estate – owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	649	1,015
Commercial real estate – owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
Commercial real estate – investor
Financing Receivable, Past Due [Line Items]
Total Past Due	12,424	23,252
90 Days or Greater Past Due	9,047	11,122
Loans Not Past Due	3,791,927	3,468,212
Total	3,804,351	3,491,464
Commercial real estate – investor | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	3,377	8,897
Commercial real estate – investor | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	0	3,233
Residential real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	13,303	22,558
90 Days or Greater Past Due	1,739	4,238
Loans Not Past Due	2,176,045	2,286,901
Total	2,189,348	2,309,459
Residential real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	11,031	15,156
Residential real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	533	3,164
Consumer
Financing Receivable, Past Due [Line Items]
Total Past Due	5,291	5,079
90 Days or Greater Past Due	3,298	3,568
Loans Not Past Due	308,951	334,383
Total	314,242	339,462
Consumer | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	1,873	978
Consumer | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 120	$ 533