Discontinued operations - Narrative (Details) $ in Millions		12 Months Ended
	Jun. 29, 2015	Dec. 31, 2015 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pro rata distribution to stockholders (as a percent)	98.50%
Conversion ratio for every share of Tegna common stock owned by stockholders	0.5
Shares held by Tegna after distribution (as a percent)	1.50%
Tegna to own shares for a period, not to exceed	5 years
Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal of other segment		$ 26.3
Loss on disposal of other segment, net of tax		$ 14.8