Segment Information - Segment Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segments Information
Total segment income	$ 44,291	$ 110,664	$ 136,521	$ 69,904	$ 32,128	$ 87,572	$ 104,053	$ 55,437	$ 361,380	$ 279,190	$ 240,273
Selling, general, and administrative expense									(853,160)	(691,884)	(634,890)
Depreciation and amortization									(31,545)	(24,695)	(24,101)
Other interest expense, net									(42,959)	(48,318)	(53,377)
Tax Receivable Agreement liability adjustment									99,687
Loss and expense on debt restructure									(849)	(6,270)
Other expense, net											1
Income before income taxes									389,956	206,966	175,649
As Reported
Segments Information
Total segment income										281,368	244,510
Income before income taxes										209,144	179,886
Adjustment
Segments Information
Total segment income										(2,178)	(4,237)
Income before income taxes										(2,178)	(4,237)
Operating Segments
Segments Information
Total segment income									370,995	290,631	255,815
Depreciation and amortization									(31,545)	(24,695)	(21,870)
Other interest expense, net									(5,881)	(5,414)	(16,047)
Corporate, Non-Segment
Segments Information
Selling, general, and administrative expense									(5,373)	(4,382)	(2,689)
Depreciation and amortization											(2,231)
Other interest expense, net									(37,078)	(42,904)	(37,330)
Consumer services and plans | Operating Segments
Segments Information
Total segment income									98,371	89,046	80,522
Depreciation and amortization									(3,688)	(3,780)	(3,627)
Other interest expense, net									2	(19)	(32)
Retail | Operating Segments
Segments Information
Total segment income									272,624	201,585	175,293
Depreciation and amortization									(27,857)	(20,915)	(18,243)
Other interest expense, net									$ (5,883)	(5,395)	(16,015)
Retail | Operating Segments | As Reported
Segments Information
Total segment income										203,800	179,500
Retail | Operating Segments | Adjustment
Segments Information
Total segment income										$ 2,200	$ 4,200