Finance Receivables and Allowance for Credit Losses - Schedule of Receivables for which Contractually Required Payments would not be Collected (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2016
Anchor BanCorp Wisconsin Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Effective date of acquisition	May 01, 2016
Founders Financial Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Effective date of acquisition	Jan. 01, 2015