Note 13 - Employee Retirement Plans - International Defined Benefit Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair value of plan assets	$ 3,225,000	$ 3,058,000	$ 3,263,000
Insurance Contracts [Member]
Fair value of plan assets	2,000	3,000	5,000
Collateralized Mortgage Backed Securities [Member]
Fair value of plan assets	0	2,000	7,000
Foreign Pension Plan [Member]
Fair value of plan assets	460,000	442,000	$ 449,000
Foreign Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets	361,000	346,000
Foreign Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets	97,000	91,000
Foreign Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets	2,000	5,000
Foreign Pension Plan [Member] | Insurance Contracts [Member]
Fair value of plan assets	2,000	3,000
Foreign Pension Plan [Member] | Insurance Contracts [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets
Foreign Pension Plan [Member] | Insurance Contracts [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets
Foreign Pension Plan [Member] | Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets	2,000	3,000
Foreign Pension Plan [Member] | Collateralized Mortgage Backed Securities [Member]
Fair value of plan assets		2,000
Foreign Pension Plan [Member] | Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets
Foreign Pension Plan [Member] | Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets
Foreign Pension Plan [Member] | Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets		2,000
Foreign Pension Plan [Member] | Cash Equivalents [Member]
Fair value of plan assets	40,000	60,000
Foreign Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets	40,000	60,000
Foreign Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets
Foreign Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets
Foreign Pension Plan [Member] | U.S. Companies [Member] | Equity Securities [Member]
Fair value of plan assets	7,000	7,000
Foreign Pension Plan [Member] | U.S. Companies [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets
Foreign Pension Plan [Member] | U.S. Companies [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets	7,000	7,000
Foreign Pension Plan [Member] | U.S. Companies [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets
Foreign Pension Plan [Member] | International Companies [Member] | Equity Securities [Member]
Fair value of plan assets	26,000	23,000
Foreign Pension Plan [Member] | International Companies [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets
Foreign Pension Plan [Member] | International Companies [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets	26,000	23,000
Foreign Pension Plan [Member] | International Companies [Member] | Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets
Foreign Pension Plan [Member] | International Companies [Member] | Fixed Income Securities [Member]
Fair value of plan assets	385,000	347,000
Foreign Pension Plan [Member] | International Companies [Member] | Fixed Income Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets	321,000	286,000
Foreign Pension Plan [Member] | International Companies [Member] | Fixed Income Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets	64,000	61,000
Foreign Pension Plan [Member] | International Companies [Member] | Fixed Income Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets