Income taxes (Details) $ in Millions	3 Months Ended
Mar. 31, 2020 USD ($)
Income Tax Disclosure [Abstract]
CARES Act, reduction in tax payments	$ 7

Coronavirus Aid, Relief, and Economic Security (CARES) Act, Reduction In Tax Payments

No definition available.

Name:	tgna_CoronavirusAidReliefandEconomicSecurityCARESActReductionInTaxPayments
Namespace Prefix:	tgna_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration