Note 16 - Weighted-average Asset Allocation By Assets Category (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Major US Plans [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	100.00%	100.00%
Major US Plans [Member] | Equity Securities [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	16.00%	15.00%
Major US Plans [Member] | Equity Securities [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	12.00%
Major US Plans [Member] | Equity Securities [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	18.00%
Major US Plans [Member] | Debt Securities [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	33.00%	35.00%
Major US Plans [Member] | Debt Securities [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	32.00%
Major US Plans [Member] | Debt Securities [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	38.00%
Major US Plans [Member] | Real Estate [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	3.00%	3.00%
Major US Plans [Member] | Real Estate [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	0.00%
Major US Plans [Member] | Real Estate [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	6.00%
Major US Plans [Member] | Cash and Cash Equivalents [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	3.00%	1.00%
Major US Plans [Member] | Cash and Cash Equivalents [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	0.00%
Major US Plans [Member] | Cash and Cash Equivalents [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	6.00%
Major US Plans [Member] | Global Balanced Asset Allocation Funds [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	14.00%	13.00%
Major US Plans [Member] | Global Balanced Asset Allocation Funds [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	10.00%
Major US Plans [Member] | Global Balanced Asset Allocation Funds [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	20.00%
Major US Plans [Member] | Other Assets [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	31.00%	33.00%
Major US Plans [Member] | Other Assets [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	25.00%
Major US Plans [Member] | Other Assets [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	35.00%
Major Non-U.S. Plans [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	100.00%	100.00%
Major Non-U.S. Plans [Member] | Equity Securities [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	3.00%	3.00%
Major Non-U.S. Plans [Member] | Equity Securities [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	1.00%
Major Non-U.S. Plans [Member] | Equity Securities [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	10.00%
Major Non-U.S. Plans [Member] | Debt Securities [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	33.00%	35.00%
Major Non-U.S. Plans [Member] | Debt Securities [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	25.00%
Major Non-U.S. Plans [Member] | Debt Securities [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	35.00%
Major Non-U.S. Plans [Member] | Real Estate [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	0.00%	0.00%
Major Non-U.S. Plans [Member] | Real Estate [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	0.00%
Major Non-U.S. Plans [Member] | Real Estate [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	6.00%
Major Non-U.S. Plans [Member] | Cash and Cash Equivalents [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	2.00%	3.00%
Major Non-U.S. Plans [Member] | Cash and Cash Equivalents [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	0.00%
Major Non-U.S. Plans [Member] | Cash and Cash Equivalents [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	6.00%
Major Non-U.S. Plans [Member] | Global Balanced Asset Allocation Funds [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	4.00%	6.00%
Major Non-U.S. Plans [Member] | Global Balanced Asset Allocation Funds [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	0.00%
Major Non-U.S. Plans [Member] | Global Balanced Asset Allocation Funds [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	10.00%
Major Non-U.S. Plans [Member] | Other Assets [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Asset allocations	58.00%	53.00%
Major Non-U.S. Plans [Member] | Other Assets [Member] | Minimum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	55.00%
Major Non-U.S. Plans [Member] | Other Assets [Member] | Maximum [Member]
Weighted Average Asset Allocation By Assets Category [Line Items]
Target asset allocations	65.00%