Consolidated Financial Statements - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) Dwelling Segment
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of loan concentration by bank to lessors and owners of Residential Buildings and Dwellings | Dwelling	2
Number of reportable segment | Segment	1
Non Residential Buildings and Dwellings [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Amount payable to lessors	$ 284,218
Amount payable to lessors in percentage	24.80%
Residential Buildings and Dwellings [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Amount payable to lessors	$ 155,616
Amount payable to lessors in percentage	13.60%
Maximum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Percentage of insurance commission revenue of total revenue	1.00%
Maximum [Member] | WSP [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Percentage of insurance commission revenue of total revenue	1.00%