Segment Information - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segments Information
Revenue	$ 670,032	$ 991,071	$ 1,067,855	$ 797,748	$ 647,311	$ 948,005	$ 993,446	$ 697,332	$ 3,526,706	$ 3,286,094	$ 2,634,998
Consumer services and plans
Segments Information
Revenue									184,773	174,600	162,598
Retail
Segments Information
Revenue									$ 3,341,933	$ 3,111,494	$ 2,472,400