Income Taxes (Details Textual) - USD ($) $ in Thousands, shares in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2017
Income Taxes [Line Items]
Income tax (expense) benefit		$ (2,113)	$ (11,590)
Estimated full year 2017 effective income tax rate		9.00%	35.00%
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				31.00%
ASU 2016-09
Income Taxes [Line Items]
Income tax (expense) benefit		$ 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