Loans Receivable, Including Loans Held For Sale - Past Due Loans (Accruing and Nonaccruing) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Receivable [Line Items]
Current	$ 2,530,063	$ 531,078
Total past due	22,174	23,644
Total Loans	2,552,237	554,722
Recorded investment in accruing loans 90 days past due	8,549	8,051
Nonaccrual loans that are current	0	0
30-89 Days Past Due
Receivable [Line Items]
Total past due	13,625	15,593
90+ Days Past Due
Receivable [Line Items]
Total past due	8,549	8,051
Commercial real estate loans
Receivable [Line Items]
Current	644	659
Total past due	0	0
Total Loans	644	659
Recorded investment in accruing loans 90 days past due	0	0
Nonaccrual loans that are current	0	0
Commercial real estate loans | 30-89 Days Past Due
Receivable [Line Items]
Total past due	0	0
Commercial real estate loans | 90+ Days Past Due
Receivable [Line Items]
Total past due	0	0
Commercial and industrial
Receivable [Line Items]
Current	2,355,496	238,025
Total past due	16,958	13,324
Total Loans	2,372,454	251,349
Recorded investment in accruing loans 90 days past due	7,466	4,962
Nonaccrual loans that are current	0	0
Commercial and industrial | 30-89 Days Past Due
Receivable [Line Items]
Total past due	9,492	8,362
Commercial and industrial | 90+ Days Past Due
Receivable [Line Items]
Total past due	7,466	4,962
Consumer loans
Receivable [Line Items]
Current	173,923	292,394
Total past due	5,216	10,320
Total Loans	179,139	302,714
Recorded investment in accruing loans 90 days past due	1,083	3,089
Nonaccrual loans that are current	0	0
Consumer loans | 30-89 Days Past Due
Receivable [Line Items]
Total past due	4,133	7,231
Consumer loans | 90+ Days Past Due
Receivable [Line Items]
Total past due	$ 1,083	$ 3,089