Summary of Significant Accounting Policies Balance Sheet Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Lessor, Lease, Description [Line Items]
Operating lease liability	$ 14,815	$ 16,200	$ 0
Operating lease right-of-use asset	$ 14,164	$ 15,500	$ 0