Note 14 - Subsequent Events (Details Textual) - Subsequent Event [Member] - USD ($) $ in Millions	Nov. 04, 2020	Nov. 03, 2020	Oct. 19, 2020
The 2030 Notes [Member]
Debt Instrument, Face Amount			$ 800
Debt Instrument, Interest Rate, Stated Percentage			4.75%
Gray's Share Repurchase Program [Member]
Stock Repurchase Program, Additional Authorized Amount	$ 150
Stock Repurchase Program, Authorized Amount	$ 220
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 70