Segment Reporting - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2018 Segment
Segment Reporting Disclosure [Line Items]
Number of business segments	6
Number of operating segments	4
Number of non-operating segments	2
Loan outstanding percent	10.00%
Pools [Member]
Segment Reporting Disclosure [Line Items]
Loan outstanding percent	38.00%
Solar Panels [Member]
Segment Reporting Disclosure [Line Items]
Loan outstanding percent	15.00%
Roofing [Member]
Segment Reporting Disclosure [Line Items]
Loan outstanding percent	11.00%
TX [Member]
Segment Reporting Disclosure [Line Items]
Loan outstanding percent	17.00%
CALIFORNIA
Segment Reporting Disclosure [Line Items]
Loan outstanding percent	11.00%
Florida [Member]
Segment Reporting Disclosure [Line Items]
Loan outstanding percent	11.00%
Geographic Concentration Risk [Member] | Midwest [Member]
Segment Reporting Disclosure [Line Items]
Aggregate percentage of loans lending	47.00%
Geographic Concentration Risk [Member] | New York
Segment Reporting Disclosure [Line Items]
Aggregate percentage of loans lending	88.00%