Secured Notes Payable and Revolving Credit Facility, Net - Schedule of Secured Notes Payable and Revolving Credit Facility (Details) - USD ($)		9 Months Ended
	Feb. 29, 2016	Sep. 30, 2017	Sep. 30, 2016	Nov. 01, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Principal Balance		$ 4,087,638,000			$ 4,408,083,000
Deferred loan costs, net		(38,810,000)			(38,546,000)
Total Debt, Net		4,048,828,000			4,369,537,000
Revolving Credit Facility With Maturity Date of August 21, 2020 [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 400,000,000
Revolving Credit Facility With Maturity Date of August 21, 2020 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Unused commitment fees (as a percent)		0.15%
Revolving Credit Facility With Maturity Date of August 21, 2020 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Unused commitment fees (as a percent)		0.20%
Secured Debt [Member] | LIBOR [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis spread		0.00%
Secured Debt [Member] | Term Loans With Effective Annual Fixed Interest Rate At 4.00% And 3.85% [Member]
Debt Instrument [Line Items]
Fixed rate debt amortization period		30 years
Secured Debt [Member] | Term Loan With Maturity Date of February 28, 2023 [Member]
Debt Instrument [Line Items]
Principal Balance	$ 580,000,000
Fixed interest rate	2.37%
Secured Debt [Member] | Term Loan With Maturity Date of February 28, 2023 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread	1.40%
Line of Credit [Member] | Revolving Credit Facility With Maturity Date of August 21, 2020 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread	1.40%
Wholly Owned Subsidiaries [Member]
Debt Instrument [Line Items]
Principal Balance		$ 3,142,138,000			3,682,083,000
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 3.00% [Member]
Debt Instrument [Line Items]
Principal Balance		0			1,000,000
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 4.14% [Member]
Debt Instrument [Line Items]
Principal Balance		0			349,933,000
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Fannie Mae Loans With Maturity Date of November 1, 2020 [Member]
Debt Instrument [Line Items]
Principal Balance		0			388,080,000
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 4.46% [Member]
Debt Instrument [Line Items]
Principal Balance		$ 0			345,759,000
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 4.00% [Member]
Debt Instrument [Line Items]
Maturity Date		Feb. 01, 2019
Principal Balance		$ 147,719,000			149,911,000
Fixed interest rate		4.00%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 3.85% [Member]
Debt Instrument [Line Items]
Maturity Date		Jun. 05, 2019
Principal Balance		$ 282,019,000			285,000,000
Fixed interest rate		3.85%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Fannie Mae Loan With Maturity Date of October 1, 2019 [Member]
Debt Instrument [Line Items]
Maturity Date		Oct. 01, 2019
Principal Balance		$ 145,000,000			145,000,000
Variable Interest Rate		LIBOR + 1.25%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Fannie Mae Loan With Maturity Date of October 1, 2019 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.25%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 2.77% [Member]
Debt Instrument [Line Items]
Maturity Date		Apr. 15, 2022
Principal Balance		$ 340,000,000			340,000,000
Variable Interest Rate		LIBOR + 1.40%
Fixed interest rate		2.77%
Swap Maturity Date		Apr. 01, 2020
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 2.77% [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.40%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 3.06% [Member]
Debt Instrument [Line Items]
Maturity Date		Jul. 27, 2022
Principal Balance		$ 180,000,000			180,000,000
Variable Interest Rate		LIBOR + 1.45%
Fixed interest rate		3.06%
Swap Maturity Date		Jul. 01, 2020
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 3.06% [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.45%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 2.64% [Member]
Debt Instrument [Line Items]
Maturity Date		Nov. 01, 2022
Principal Balance		$ 400,000,000			400,000,000
Variable Interest Rate		LIBOR + 1.35%
Fixed interest rate		2.64%
Swap Maturity Date		Nov. 01, 2020
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 2.64% [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.35%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 2.57% [Member]
Debt Instrument [Line Items]
Maturity Date		Jun. 23, 2023
Principal Balance		$ 360,000,000			360,000,000
Variable Interest Rate		LIBOR + 1.55%
Fixed interest rate		2.57%
Swap Maturity Date		Jul. 01, 2021
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 2.57% [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.55%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 3.62% [Member]
Debt Instrument [Line Items]
Maturity Date		Dec. 23, 2023
Principal Balance		$ 220,000,000			220,000,000
Variable Interest Rate		LIBOR + 1.70%
Fixed interest rate		3.62%
Swap Maturity Date		Dec. 23, 2021
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 3.62% [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.70%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 3.46% [Member]
Debt Instrument [Line Items]
Maturity Date		Jan. 01, 2024
Principal Balance		$ 300,000,000			300,000,000
Variable Interest Rate		LIBOR + 1.55%
Fixed interest rate		3.46%
Swap Maturity Date		Jan. 01, 2022
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Term Loan With Effective Annual Fixed Interest Rate At 3.46% [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.55%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Fannie Mae Loan With Maturity Date of April 1, 2025 [Member]
Debt Instrument [Line Items]
Maturity Date		Apr. 01, 2025
Principal Balance		$ 102,400,000			102,400,000
Variable Interest Rate		LIBOR + 1.25%
Fixed interest rate		2.84%
Swap Maturity Date		Mar. 01, 2020
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Fannie Mae Loan With Maturity Date of April 1, 2025 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.25%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Fannie Mae Loans With Maturity Date of December 1, 2025 [Member]
Debt Instrument [Line Items]
Maturity Date		Dec. 01, 2025
Principal Balance		$ 115,000,000			115,000,000
Variable Interest Rate		LIBOR + 1.25%
Fixed interest rate		2.76%
Swap Maturity Date		Dec. 01, 2020
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Fannie Mae Loans With Maturity Date of December 1, 2025 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.25%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Fannie Mae Loans With Maturity Date of June 1, 2027 [Member]
Debt Instrument [Line Items]
Maturity Date		Jun. 01, 2027
Principal Balance		$ 550,000,000			0
Variable Interest Rate		LIBOR + 1.37%
Fixed interest rate		3.51%
Swap Maturity Date		Jun. 01, 2022
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Fannie Mae Loans With Maturity Date of June 1, 2027 [Member] | Forecast [Member]
Debt Instrument [Line Items]
Fixed interest rate				3.16%
Wholly Owned Subsidiaries [Member] | Secured Debt [Member] | Fannie Mae Loans With Maturity Date of June 1, 2027 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.37%
Wholly Owned Subsidiaries [Member] | Line of Credit [Member] | Revolving Credit Facility With Maturity Date of August 21, 2020 [Member]
Debt Instrument [Line Items]
Maturity Date		Aug. 21, 2020
Principal Balance		$ 0			0
Variable Interest Rate		LIBOR + 1.40%
Wholly Owned Subsidiaries [Member] | Line of Credit [Member] | Revolving Credit Facility With Maturity Date of August 21, 2020 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.40%
Consolidated JV [Member] | Secured Debt [Member] | Term Loan With Maturity Date of July 21, 2019 [Member]
Debt Instrument [Line Items]
Maturity Date		Jul. 21, 2019
Principal Balance		$ 365,500,000			146,000,000
Variable Interest Rate		LIBOR + 1.55%
Consolidated JV [Member] | Secured Debt [Member] | Term Loan With Maturity Date of July 21, 2019 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.55%	1.55%
Consolidated JV [Member] | Secured Debt [Member] | Term Loan With Maturity Date of February 28, 2023 [Member]
Debt Instrument [Line Items]
Maturity Date		Feb. 28, 2023
Principal Balance		$ 580,000,000			$ 580,000,000
Variable Interest Rate		LIBOR + 1.40%
Fixed interest rate		2.37%
Swap Maturity Date		Mar. 01, 2021
Consolidated JV [Member] | Secured Debt [Member] | Term Loan With Maturity Date of February 28, 2023 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread		1.40%