Loans Receivable, Net - Aging of Recorded Investment in Past Due Loans Excluding PCI Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 70,420	$ 26,636
Greater than 90 Days Past Due	13,932	9,286
Loans Not Past Due	7,862,170	6,174,751
Total loans	7,932,590	6,201,387
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	51,275	11,231
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	5,213	6,119
Commercial and Industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	3,834	307
Greater than 90 Days Past Due	207	207
Loans Not Past Due	498,926	395,784
Total loans	502,760	396,091
Commercial and Industrial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	3,052	100
Commercial and Industrial | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	575	0
Commercial real estate – owner occupied
Financing Receivable, Past Due [Line Items]
Total Past Due	10,582	3,784
Greater than 90 Days Past Due	392	1,040
Loans Not Past Due	1,210,401	788,157
Total loans	1,220,983	791,941
Commercial real estate – owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	8,883	1,541
Commercial real estate – owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	1,307	1,203
Commercial real estate – investor
Financing Receivable, Past Due [Line Items]
Total Past Due	29,213	4,111
Greater than 90 Days Past Due	7,466	2,792
Loans Not Past Due	3,302,449	2,280,587
Total loans	3,331,662	2,284,698
Commercial real estate – investor | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	19,152	381
Commercial real estate – investor | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	2,595	938
Residential real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	21,803	14,507
Greater than 90 Days Past Due	3,234	2,859
Loans Not Past Due	2,436,838	2,306,314
Total loans	2,458,641	2,320,821
Residential real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	18,363	8,161
Residential real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	206	3,487
Consumer
Financing Receivable, Past Due [Line Items]
Total Past Due	4,988	3,927
Greater than 90 Days Past Due	2,633	2,388
Loans Not Past Due	413,556	403,909
Total loans	418,544	407,836
Consumer | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	1,825	1,048
Consumer | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 530	$ 491