Commercial Loans Receivables and Allowance for Loan Loss (Commercial Loans Receivables by Class and Credit Quality Indicator) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018
Financing Receivable Recorded Investment [Line Items]
Weighted average contractual interest rate, commercial	5.50%	4.60%
Weighted average months to maturity, commercial	5 months	6 months
Direct Commercial Loans [Member]
Risk profile based on payment activity
Financing Receivable, Gross	$ 30,414	$ 16,368
Direct Commercial Loans [Member] | Performing [Member]
Risk profile based on payment activity
Financing Receivable, Gross	30,414	16,368
Direct Commercial Loans [Member] | Watch list [Member]
Risk profile based on payment activity
Financing Receivable, Gross	0	0
Direct Commercial Loans [Member] | Nonperforming [Member]
Risk profile based on payment activity
Financing Receivable, Gross	0	0
Participation Commercial Loans [Member]
Risk profile based on payment activity
Financing Receivable, Gross	332	275
Participation Commercial Loans [Member] | Performing [Member]
Risk profile based on payment activity
Financing Receivable, Gross	332	275
Participation Commercial Loans [Member] | Watch list [Member]
Risk profile based on payment activity
Financing Receivable, Gross	0	0
Participation Commercial Loans [Member] | Nonperforming [Member]
Risk profile based on payment activity
Financing Receivable, Gross	$ 0	$ 0