Income Taxes (Details Textual) - USD ($) $ in Thousands, shares in Millions	1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
	Jan. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2017
Income Taxes [Line Items]
Income tax (expense) benefit		$ (8,722)		$ (6,448)	$ (10,835)	$ (18,038)
Estimated full year 2017 effective income tax rate		43.00%		37.00%	25.00%	36.00%
Warrant Exercise
Income Taxes [Line Items]
Income tax (expense) benefit			$ 5,000
Scenario, Forecast
Income Taxes [Line Items]
Estimated full year 2017 effective income tax rate							32.00%
ASU 2016-09
Income Taxes [Line Items]
Income tax (expense) benefit		$ 0			$ 1,000
ASU 2016-09 | Scenario, Forecast
Income Taxes [Line Items]
Income tax (expense) benefit							$ 2,000
Comcast Corporation
Income Taxes [Line Items]
Stock warrants exercised	1.4