Other Assets Goodwill (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill	$ 320,639	$ 331,884	$ 0
Goodwill, Other Increase (Decrease)	(381)	0
Goodwill, Impairment Loss	(9,220)	0
Goodwill, Written off Related to Sale of Business Unit	2,144	0
Equity One Inc. [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	$ 500
Goodwill, Acquired During Period		$ 331,884

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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