Real Estate and Loans Receivable - Schedule of Revenue by Operator (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Investment And Revenue From External Customers [Line Items]
Total Revenue	$ 153,283	$ 126,555	$ 126,300	$ 134,999	$ 131,546	$ 114,570	$ 99,801	$ 95,961	$ 541,137	$ 441,878	$ 312,532
Revenue [Member] | Credit Concentration Risk [Member]
Investment And Revenue From External Customers [Line Items]
Total Revenue									$ 541,137	$ 441,878
Percentage of Total Revenue									100.00%	100.00%
Revenue [Member] | Credit Concentration Risk [Member] | Prime [Member]
Investment And Revenue From External Customers [Line Items]
Total Revenue									$ 120,558	$ 104,325
Percentage of Total Revenue									22.30%	23.60%
Revenue [Member] | Credit Concentration Risk [Member] | Median [Member]
Investment And Revenue From External Customers [Line Items]
Total Revenue									$ 93,425	$ 78,540
Percentage of Total Revenue									17.30%	17.80%
Revenue [Member] | Credit Concentration Risk [Member] | Ernest [Member]
Investment And Revenue From External Customers [Line Items]
Total Revenue									$ 67,742	$ 61,988
Percentage of Total Revenue									12.50%	14.00%
Revenue [Member] | Credit Concentration Risk [Member] | RCCH [Member]
Investment And Revenue From External Customers [Line Items]
Total Revenue									$ 52,720	$ 28,567
Percentage of Total Revenue									9.70%	6.40%
Revenue [Member] | Credit Concentration Risk [Member] | Other Operators [Member]
Investment And Revenue From External Customers [Line Items]
Total Revenue									$ 206,692	$ 168,458
Percentage of Total Revenue									38.20%	38.20%