Note 11 - Segment Data (Details) - Financial Information by Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues
Revenues	$ 272,466	$ 259,376	$ 515,290	$ 527,299
Operating Income (loss)
Operating Income	31,816	21,596	52,573	46,457
Fluids Systems & Engineering [Member]
Revenues
Revenues	241,386	233,964	452,786	481,303
Operating Income (loss)
Operating Income	27,571	17,684	43,311	40,306
Mats and Integrated Services [Member]
Revenues
Revenues	31,080	25,412	62,504	45,996
Operating Income (loss)
Operating Income	13,653	10,341	27,026	18,821
Corporate Segment [Member]
Operating Income (loss)
Operating Income	$ (9,408)	$ (6,429)	$ (17,764)	$ (12,670)