Acquisition Schedule of Net Assets Acquired - Additional Information (Details) - USD ($) $ in Thousands			9 Months Ended
	Sep. 06, 2019	May 01, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition [Line Items]
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Deposits Contractual Amount			$ 471,000
Santandar Bank N.A. [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 329,530
Goodwill, Acquired During Period	29,430
Loans	100,025
Business Combination, Acquired Receivables, Gross Contractual Amount	101,200
Business Combination Acquired Receivables Fair Value Adjustment	(1,200)
Deposits	471,383
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Deposits Fair Value Adjustment	400
Intangible assets	$ 5,277
Business Combination, Acquisition Related Costs			$ 3,700
Garfield Acquisition Corp [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross		$ 58,961
Business Combination, Consideration Transferred, Other		$ 17,400
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares		2,745,098
Goodwill, Acquired During Period		$ 19,022
Loans		184,506
Business Combination, Acquired Receivables, Gross Contractual Amount		183,700
Business Combination Acquired Receivables Fair Value Adjustment		4,300
Business Combination, Acquired Receivables, Contractual Adjustments		5,100
Deposits		141,281
Intangible assets		$ 1,248
Business Combination, Acquisition Related Costs				$ 1,600