Loans Receivable, Net - Aging of Recorded Investment in Past Due Loans Excluding PCI Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
90 Days or Greater Past Due	$ 27,126	$ 9,286
Total Past Due	63,780	26,636
Loans Not Past Due	7,692,326	6,174,751
Total ending loan balance	7,756,106	6,201,387
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	29,096	11,231
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	7,558	6,119
Commercial and industrial
Financing Receivable, Past Due [Line Items]
90 Days or Greater Past Due	327	207
Total Past Due	4,005	307
Loans Not Past Due	466,651	395,784
Total ending loan balance	470,656	396,091
Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	3,050	100
Commercial and industrial | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	628	0
Commercial real estate – owner occupied
Financing Receivable, Past Due [Line Items]
90 Days or Greater Past Due	7,871	1,040
Total Past Due	8,886	3,784
Loans Not Past Due	1,136,179	788,157
Total ending loan balance	1,145,065	791,941
Commercial real estate – owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	1,015	1,541
Commercial real estate – owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	0	1,203
Commercial real estate - investor
Financing Receivable, Past Due [Line Items]
90 Days or Greater Past Due	11,122	2,792
Total Past Due	23,252	4,111
Loans Not Past Due	3,468,212	2,280,587
Total ending loan balance	3,491,464	2,284,698
Commercial real estate - investor | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	8,897	381
Commercial real estate - investor | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	3,233	938
Residential real estate
Financing Receivable, Past Due [Line Items]
90 Days or Greater Past Due	4,238	2,859
Total Past Due	22,558	14,507
Loans Not Past Due	2,286,901	2,306,314
Total ending loan balance	2,309,459	2,320,821
Residential real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	15,156	8,161
Residential real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	3,164	3,487
Consumer
Financing Receivable, Past Due [Line Items]
90 Days or Greater Past Due	3,568	2,388
Total Past Due	5,079	3,927
Loans Not Past Due	334,383	403,909
Total ending loan balance	339,462	407,836
Consumer | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	978	1,048
Consumer | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 533	$ 491