Note 5 - Fair Value of Financial Instruments - Derivative Instruments in Other Comprehensive Income (Loss) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Balance in Other comprehensive income (loss) beginning of period	$ 1,941,437
Balance in Other comprehensive income (loss) end of period	1,949,879
Cross Currency Interest Rate Contract [Member] | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member]
Balance in Other comprehensive income (loss) beginning of period	3,366
Gain or (loss) recognized in Other comprehensive income (loss)	(13,900)	[1]
Amount reclassified from Other comprehensive income (loss) into earnings	11,102
Balance in Other comprehensive income (loss) end of period	$ 568

[1] The amount of gain or (loss) recognized in Other comprehensive income (loss) is net of tax of $1.1 million.