Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Sep. 28, 2017
Accounting Policies [Abstract]
Stock dividend paid to company stockholders			5.00%
Embedded Derivative [Line Items]
Fair market value of embedded derivatives at the midpoint of the inputs	$ 65,846	$ 76,413
Minimum
Embedded Derivative [Line Items]
Fair market value of embedded derivatives at the midpoint of the inputs	65,510	76,215
Maximum
Embedded Derivative [Line Items]
Fair market value of embedded derivatives at the midpoint of the inputs	$ 66,003	$ 76,874