Segments Information (Restated) - Segment Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segments Information
Total segment income	$ 110,664	$ 87,572	$ 317,089	$ 247,062
Selling, general, and administrative expense	(236,174)	(186,255)	(640,108)	(536,966)
Depreciation and amortization	(8,382)	(6,219)	(22,819)	(18,144)
Other interest expense, net	(11,012)	(12,715)	(30,973)	(38,040)
Tax Receivable Agreement liability adjustment	(96)		(79)
Other expense, net				(2)
Income before income taxes	92,142	70,535	266,734	194,169
Operating Segments
Segments Information
Total segment income	113,669	90,560	327,066	252,775
Depreciation and amortization	(8,154)	(6,219)	(22,476)	(18,144)
Other interest expense, net	(1,424)	(1,486)	(4,380)	(4,262)
Corporate, Non-Segment
Segments Information
Selling, general, and administrative expense	(2,037)	(1,091)	(6,461)	(2,420)
Depreciation and amortization	(228)		(343)
Other interest expense, net	(9,588)	(11,229)	(26,593)	(33,778)
Consumer services and plans | Operating Segments
Segments Information
Total segment income	21,675	19,847	71,887	63,948
Depreciation and amortization	(888)	(926)	(2,889)	(2,777)
Other interest expense, net	(1)	(4)	(5)	(12)
Retail | Operating Segments
Segments Information
Total segment income	91,994	70,713	255,179	188,827
Depreciation and amortization	(7,266)	(5,293)	(19,587)	(15,367)
Other interest expense, net	$ (1,423)	$ (1,482)	$ (4,375)	$ (4,250)