Note 14 - Accumulated Other Comprehensive Income ("AOCI") - Components of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Balance	$ 5,402,874	$ 5,181,951
Balance at the end of the year	5,359,546	5,317,357
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	6,335	6,616
Other comprehensive income before reclassifications	503	2,510
Amounts reclassified from AOCI
Net current-period other comprehensive income	503	2,510
Balance at the end of the year	6,838	9,126
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Balance	406	398
Other comprehensive income before reclassifications	28	2
Amounts reclassified from AOCI
Net current-period other comprehensive income	28	2
Balance at the end of the year	434	400
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance	(975)	(1,426)
Other comprehensive income before reclassifications	188	(604)
Amounts reclassified from AOCI
Net current-period other comprehensive income	188	(604)
Balance at the end of the year	(787)	(2,030)
AOCI Attributable to Parent [Member]
Balance	5,766	5,588
Other comprehensive income before reclassifications	719	1,908
Amounts reclassified from AOCI
Net current-period other comprehensive income	719	1,908
Balance at the end of the year	$ 6,485	$ 7,496