Goodwill and intangible assets (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Changes in the goodwill
Net balance at the beginning of the period	$ 164,887	$ 130,794
Additions		34,093
Net balance at the end of the period	$ 164,887	164,887
Changes in the goodwill and other indefinite lived intangible assets, on a net basis
Net balance at the beginning of the period	$ 222,929	172,850
Additions		50,079
Net balance at the end of the period	$ 222,929	222,929
Broadcast license
Changes in other indefinite-lived intangible assets
Net balance at the beginning of the period	$ 41,356	41,356
Additions
Net balance at the end of the period	$ 41,356	41,356
Brands
Changes in other indefinite-lived intangible assets
Net balance at the beginning of the period	$ 15,986
Additions		15,986
Net balance at the end of the period	$ 15,986	15,986
Other intangibles
Changes in other indefinite-lived intangible assets
Net balance at the beginning of the period	$ 700	700
Additions
Net balance at the end of the period	$ 700	$ 700