Description of Business and Organization Description of Business and Organization Narrative (Details) (USD $)	0 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended			0 Months Ended		0 Months Ended
	Oct. 06, 2013 entity	Dec. 31, 2013 sqft entity	Oct. 06, 2013 Predecessor [Member]	Dec. 31, 2012 Predecessor [Member]	Dec. 31, 2011 Predecessor [Member]	Dec. 31, 2013 Predecessor [Member] sqft	Sep. 28, 2012 Predecessor [Member] New York State Supreme Court, New York County [Member]	Dec. 31, 2013 Secured Revolving and Term Credit Facility [Member]	Oct. 06, 2013 Accredited Investor [Member]	Oct. 06, 2013 Non-accredited Prior Investors [Member]	Oct. 06, 2013 Common Class A [Member]	Oct. 06, 2013 Common Class A [Member] Accredited Investor [Member]	Oct. 06, 2013 Common Class B [Member] Accredited Investor [Member]	Dec. 31, 2013 Office Building [Member] sqft office_and_property	Dec. 31, 2013 Office Building [Member] Manhattan [Member] sqft office_and_property	Dec. 31, 2013 Office Building [Member] Fairfield County, Connecticut and Westchester County, New York [Member] office_and_property sqft	Dec. 31, 2013 Retail Site [Member] Manhattan and Westport, Connecticut [Member] sqft	Dec. 31, 2013 Retail Site [Member] Manhattan [Member] office_and_property sqft	Dec. 31, 2013 Retail Site [Member] Westport, Connecticut [Member] office_and_property	Dec. 31, 2013 Other Property [Member] Stamford, Connecticut [Member] sqft	Dec. 31, 2013 Consolidated Properties [Member] Development Parcel [Member] Predecessor [Member] parcel
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Area of real estate property		8,400,000				380,000								7,700,000	5,900,000	1,800,000	204,175	418,377		380,000
Number of properties														12	7	5		4	2		1
Issuance of Common Stock (in shares)											82,200,000	12,100,000	1,100,000
Share price (in dollars per share)											$ 13.00
Operating partnership units issued during period (in shares)									149,000,000
Operating partnership units issued during period	$ 2,800,000,000								$ 2,100,000,000	$ 733,300,000
Current borrowing capacity								800,000,000.0
Maximum borrowing capacity								1,250,000,000.00
OP units owned by the Company, percent		38.90%
Number of entities to be treated as taxable REIT subsidiary		2
Damages awarded							55,000,000.0
Percent of damages awarded required to be in cash							80.00%
Maximum percent of freely-tradable common stock or partnership units							20.00%
Contributions			$ 8,223,000	$ 2,107,000	$ 2,153,000		$ 55,000,000.0
Number of entities acquired	4