Segment Information - Depreciation and Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segments Information
Depreciation and amortization	$ 31,545	$ 24,695	$ 24,101
Operating Segments
Segments Information
Depreciation and amortization	31,545	24,695	21,870
Corporate, Non-Segment
Segments Information
Depreciation and amortization			2,231
Consumer services and plans | Operating Segments
Segments Information
Depreciation and amortization	3,688	3,780	3,627
Retail | Operating Segments
Segments Information
Depreciation and amortization	$ 27,857	$ 20,915	$ 18,243