Investments in and Advances to Joint Ventures - Condensed Combined Financial Information of Company's Unconsolidated Joint Venture Investments (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Condensed Combined Balance Sheets
Land	$ 970,008	$ 1,738,792
Buildings	3,634,232	5,733,451
Fixtures and tenant improvements	508,270	693,280
Total real estate rental property	5,112,510	8,165,523
Less: Accumulated depreciation	(1,284,446)	(1,953,479)
Real estate rental property, net	3,828,064	6,212,044
Construction in progress and land	58,717	82,480
Total real estate assets, net	3,886,781	6,294,524
Other assets, net	111,776	210,059
Total assets	4,620,092	7,170,073
Mortgage debt	185,004	641,082
Total liabilities	2,645,101	4,272,635
Total liabilities and equity	4,620,092	7,170,073
Company's share of accumulated equity	100,548	132,710
Redeemable preferred equity, net	204,078	277,776
Basis differentials	(16,004)	(24,973)
Deferred development fees, net of portion related to the Company's interest	(2,717)	(3,065)
Amounts payable to the Company	1,965	1,365
Investments in and Advances to Joint Ventures, net	287,870	383,813
Unconsolidated Joint Ventures [Member]
Condensed Combined Balance Sheets
Land	907,273	1,126,703
Buildings	2,541,879	3,057,072
Fixtures and tenant improvements	207,064	213,989
Total real estate rental property	3,656,216	4,397,764
Less: Accumulated depreciation	(936,932)	(962,038)
Real estate rental property, net	2,719,284	3,435,726
Construction in progress and land	55,522	53,928
Total real estate assets, net	2,774,806	3,489,654
Cash and restricted cash	92,078	155,894
Receivables, net	43,933	51,396
Other assets, net	114,771	174,832
Total assets	3,025,588	3,871,776
Mortgage debt	2,000,750	2,501,163
Notes and accrued interest payable to the Company	1,965	1,365
Other liabilities	123,524	156,076
Total liabilities	2,126,239	2,658,604
Redeemable preferred equity – SITE Centers	280,428	345,149
Accumulated equity	618,921	868,023
Total liabilities and equity	$ 3,025,588	$ 3,871,776