Note 8 - Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Loss) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Balance	$ 927,556
Activity in the period	(16,221)
Balance	1,470,020
Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Balance	(10,836)	[1]
Cumulative effect adjustment (b)		[1],[2]
Activity in the period	763	[1]
Balance	(10,073)	[1]
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member]
Balance	9,795
Cumulative effect adjustment (b)	(9,795)	[1],[2]
Activity in the period
Balance
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Balance	(62,627)
Cumulative effect adjustment (b)		[1],[2]
Activity in the period	(16,984)
Balance	(79,611)
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Balance	(63,668)
Cumulative effect adjustment (b)	(9,795)	[1],[2]
Activity in the period	(16,221)
Balance	$ (89,684)

[1] The balances at June 30, 2018 and December 30, 2017 are net of taxes of $0.2 million and $1.4 million, respectively.

[2] The Company adopted ASU 2016-01 on December 31, 2017 on a modified retrospective basis, recognizing the cumulative effect as a $9.8 million increase to retained earnings. See Note 1, Summary of Significant Accounting Policies and Other Information, for further discussion.