Summary of Significant Accounting Policies Schedule of Variable Interest Entities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Current Fiscal Year End Date	--12-31
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	$ 16,551	$ 8,175
Noncontrolling Interest in Variable Interest Entity	17,572	17,565
Real Estate [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	172,736	86,440
Cash and Cash Equivalents [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 4,993	$ 3,444