Note 1 - Business and Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Notes Tables

Schedule Of Estimated Useful Lives [Table Text Block]

Buildings (in years)		25
Leasehold improvements (in years)	15	-	20
Machinery and equipment — manufacturing and drilling (in years)		10
Machinery and equipment — computers (in years)	3	-	5
Office equipment — furniture and fixtures (in years)	5	-	15
Office equipment — other (in years)	5	-	10
Automobiles (in years)	5	-	7

Schedule of Weighted Average Number of Shares [Table Text Block]

	Year Ended December 31,
	2016		2015		2014
	(In thousands)
Weighted average number of shares used in computation of basic earnings per share		49,469		48,562		45,508
Add:
Additional shares from the assumed exercise of employee stock options		671		625		351
Weighted average number of shares used in computation of diluted earnings per share		50,140		49,187		45,859