Loans Receivable, Net - Aging of Recorded Investment in Past Due Loans Excluding PCI Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Total loans receivable	$ 7,820,790	$ 7,756,106
Total Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	27,947	63,780
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	2,690	29,096
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	3,674	7,558
90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	21,583	27,126
Loans Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	7,792,843	7,692,326
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total loans receivable	474,919	470,656
Commercial and industrial | Total Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	1,649	4,005
Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	1,290	3,050
Commercial and industrial | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	1	628
Commercial and industrial | 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	358	327
Commercial and industrial | Loans Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	473,270	466,651
Commercial real estate – owner occupied
Financing Receivable, Past Due [Line Items]
Total loans receivable	1,045,514	1,145,065
Commercial real estate – owner occupied | Total Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	8,347	8,886
Commercial real estate – owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	165	1,015
Commercial real estate – owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	732	0
Commercial real estate – owner occupied | 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	7,450	7,871
Commercial real estate – owner occupied | Loans Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	1,037,167	1,136,179
Commercial real estate – investor
Financing Receivable, Past Due [Line Items]
Total loans receivable	3,836,230	3,491,464
Commercial real estate – investor | Total Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	10,382	23,252
Commercial real estate – investor | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	1,046	8,897
Commercial real estate – investor | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	818	3,233
Commercial real estate – investor | 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	8,518	11,122
Commercial real estate – investor | Loans Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	3,825,848	3,468,212
Residential real estate
Financing Receivable, Past Due [Line Items]
Total loans receivable	2,168,545	2,309,459
Residential real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	3,742	22,558
Residential real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	0	15,156
Residential real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	1,586	3,164
Residential real estate | 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	2,156	4,238
Residential real estate | Loans Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans receivable	2,164,803	2,286,901
Consumer
Financing Receivable, Past Due [Line Items]
Total loans receivable	2,464,127	2,648,921
Consumer | Home Equity Loans And Lines And Other Consumer
Financing Receivable, Past Due [Line Items]
Total loans receivable	295,582	339,462
Consumer | Total Past Due | Home Equity Loans And Lines And Other Consumer
Financing Receivable, Past Due [Line Items]
Total loans receivable	3,827	5,079
Consumer | 30-59 Days Past Due | Home Equity Loans And Lines And Other Consumer
Financing Receivable, Past Due [Line Items]
Total loans receivable	189	978
Consumer | 60-89 Days Past Due | Home Equity Loans And Lines And Other Consumer
Financing Receivable, Past Due [Line Items]
Total loans receivable	537	533
Consumer | 90 Days or Greater Past Due | Home Equity Loans And Lines And Other Consumer
Financing Receivable, Past Due [Line Items]
Total loans receivable	3,101	3,568
Consumer | Loans Not Past Due | Home Equity Loans And Lines And Other Consumer
Financing Receivable, Past Due [Line Items]
Total loans receivable	$ 291,755	$ 334,383