Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Summary Of Significant Accounting Policies [Line Items]
Operating lease right-of-use assets	$ 64,615	$ 69,100	$ 0
Operating Lease, Liability	$ 70,575	$ 75,200