Commitments and Contingencies (Textual) (Details) $ in Millions		9 Months Ended
	Apr. 02, 2015 USD ($)	Sep. 30, 2016 USD ($)	Jul. 02, 2016 USD ($) a	Dec. 03, 2015 USD ($)
Property Subject to or Available for Operating Lease [Line Items]
Associated letter of credit		$ 10.0
Future capital expenditures for tenant improvements		36.4
Future capital expenditures for capital improvements		5.9
Development And Redevelopment [Member]
Property Subject to or Available for Operating Lease [Line Items]
Contractual obligations		144.3
Subaru of America [Member]
Property Subject to or Available for Operating Lease [Line Items]
NTE Amount				$ 77.3
TB-BDN Plymouth Apartments [Member]
Property Subject to or Available for Operating Lease [Line Items]
Guarantor obligations, current carrying value		3.2
Construction Loan		56.0
1919 Venture [Member]
Property Subject to or Available for Operating Lease [Line Items]
Guarantor obligations, current carrying value		88.9
PJP VII [Member]
Property Subject to or Available for Operating Lease [Line Items]
Guarantor obligations, current carrying value		0.5
A618 Market Street
Property Subject to or Available for Operating Lease [Line Items]
Contingent consideration, liability	$ 2.0	1.7
Fair value of contingent consideration	1.6
Interest expense	$ 2.0
Garza Land Acquisition [Member]
Property Subject to or Available for Operating Lease [Line Items]
Acreage of land | a			34.6
Area of land under agreement to sell | a			9.5
Infrastructure improvements to land, estimated cost			$ 5.8
Put Option [Member]
Property Subject to or Available for Operating Lease [Line Items]
Purchase price		$ 35.0
Minimum [Member]
Property Subject to or Available for Operating Lease [Line Items]
Lease terms		5 years
Maximum [Member]
Property Subject to or Available for Operating Lease [Line Items]
Lease terms		73 years