Note 10 - Financial Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fluids Systems [Member]
Revenues-
Revenues	$ 140,344	$ 241,386	$ 312,246	$ 452,786
Operating Income (loss)-
Operating Income (loss)	(223)	27,571	(1,925)	43,311
Mats and Integrated Services [Member]
Revenues-
Revenues	23,300	31,080	59,862	62,504
Operating Income (loss)-
Operating Income (loss)	6,555	13,653	22,202	27,026
Corporate Segment [Member]
Operating Income (loss)-
Operating Income (loss)	(8,014)	(9,408)	(15,831)	(17,764)
Revenues	163,644	272,466	372,108	515,290
Operating Income (loss)	$ (1,682)	$ 31,816	$ 4,446	$ 52,573