Schedule IV - Changes in Mortgage Loans Excluding Unamortized Loan Issue Costs (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Mortgage Loans On Real Estate [Abstract]
Balance at beginning of year	$ 248,335	$ 1,274,995	$ 1,213,283
New mortgage loans and additional advances on existing loans	1,128,695	193,590	61,712
Exchange rate fluctuations	(3,640)	9,785
Mortgage loans on real estate including additions during year	1,373,390	1,478,370	1,274,995
Collection of principal	(1,160,070)	(1,230,035)
Deductions during year	(1,160,070)	(1,230,035)
Balance at end of year	$ 213,320	$ 248,335	$ 1,274,995