Segments Information - Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Segments Information
Assets	$ 2,924,050	$ 2,561,477
Operating Segments
Segments Information
Assets	2,698,882	2,258,830
Corporate, Non-Segment
Segments Information
Assets	225,168	302,647
Consumer services and plans | Operating Segments
Segments Information
Assets	143,141	180,295
Retail | Operating Segments
Segments Information
Assets	$ 2,555,741	$ 2,078,535