Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jul. 31, 2020	Dec. 31, 2019
Assets:
Cash and cash equivalents	$ 413,327		$ 106,363
Non-mortgage loans receivable, net	57,077		63,724
Debt Securities, Available-for-sale	237,553		237,360
Liabilities:
Long-term debt, gross	11,983,071		12,245,802
Redeemable OP Unitholder interests, Fair Value	146,000		171,200
Brookdale Senior Living
Assets:
Cash and cash equivalents		$ 162,000
Stock warrants		28,000
Non-mortgage loans receivable, net		45,000
Secured/mortgage loans and other, net
Assets:
Debt Securities, Held-to-maturity	555,840		645,546
Debt Securities, Held-to-maturity, Fair Value	508,707		646,925
Secured/mortgage loans and other, net | Brookdale Senior Living
Assets:
Debt Securities, Held-to-maturity		$ 78,000
Government-Sponsored Pooled Loan Investments
Assets:
Debt Securities, Available-for-sale	49,727		59,066
Non-mortgage loans receivable, net
Assets:
Non-mortgage loans receivable, net	57,077		63,724
Non-mortgage loans receivable, fair value	57,009		63,538
Fair Value
Assets:
Cash and Cash Equivalents, Fair Value Disclosure	413,327		106,363
Escrow deposits and restricted cash	38,313		39,739
Derivative Asset	2		738
Liabilities:
Long-term Debt, Fair Value	13,075,337		12,778,758
Derivative Liability	28,338		12,987
Redeemable OP Unitholder interests, Fair Value	145,983		171,178
Fair Value | Brookdale Senior Living
Assets:
Stock warrants	50,098		0
Fair Value | Secured/mortgage loans and other, net
Assets:
Debt Securities, Held-to-maturity, Fair Value	508,707		646,925
Fair Value | Debt Securities
Assets:
Debt Securities, Available-for-sale	237,553		237,360
Fair Value | Government-Sponsored Pooled Loan Investments
Assets:
Debt Securities, Available-for-sale	49,727		59,066
Fair Value | Non-mortgage loans receivable, net
Assets:
Non-mortgage loans receivable, fair value	57,009		63,538
Carrying Amount
Assets:
Cash and cash equivalents	413,327		106,363
Escrow deposits and restricted cash	38,313		39,739
Derivative Asset	2		738
Liabilities:
Long-term debt, gross	11,983,071		12,245,802
Derivative Liability	28,338		12,987
Redeemable Noncontrolling Interest, Equity, Carrying Amount	145,983		171,178
Carrying Amount | Brookdale Senior Living
Assets:
Stock warrants	50,098		0
Carrying Amount | Secured/mortgage loans and other, net
Assets:
Debt Securities, Held-to-maturity	555,840		645,546
Carrying Amount | Debt Securities
Assets:
Debt Securities, Available-for-sale	237,553		237,360
Carrying Amount | Government-Sponsored Pooled Loan Investments
Assets:
Debt Securities, Available-for-sale	49,727		59,066
Carrying Amount | Non-mortgage loans receivable, net
Assets:
Non-mortgage loans receivable, net	$ 57,077		$ 63,724