Other Assets Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill, Gross	$ 314,552		$ 316,858	$ 331,884
Goodwill, Impaired, Accumulated Impairment Loss	(409)		(2,715)	0
Goodwill	314,143		314,143	$ 331,884
Goodwill, Impairment Loss	0		(12,628)
Goodwill, Other Increase (Decrease)	0		(1,159)
Impairment of Real Estate	1,672	$ 374
Equity One Inc. [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	0		500
Accumulated Impairment Losses [Member]
Goodwill [Line Items]
Goodwill, Impairment Loss	0		(12,628)
Goodwill, Other Increase (Decrease)	0		0
Accumulated Impairment Losses [Member] | Equity One Inc. [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	0		0
Goodwill, Gross [Member]
Goodwill [Line Items]
Goodwill, Impairment Loss	0		0
Goodwill, Other Increase (Decrease)	0		(1,159)
Goodwill, Gross [Member] | Equity One Inc. [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	0		500
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Goodwill [Line Items]
Goodwill, Impairment Loss	0		0
Goodwill, Written off Related to Sale of Business Unit	0		(4,454)
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Accumulated Impairment Losses [Member]
Goodwill [Line Items]
Goodwill, Impairment Loss	(1,779)		(9,913)
Goodwill, Written off Related to Sale of Business Unit	(527)		0
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Goodwill, Gross [Member]
Goodwill [Line Items]
Goodwill, Impairment Loss	(1,779)		(9,913)
Goodwill, Written off Related to Sale of Business Unit	$ (527)		$ (4,454)