Note 8 - Segment Reporting (Details) - Summary of Revenues, Gross Profit and Operating Income (Loss) by Geographic Region (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	$ 322,868	$ 242,100	$ 629,102	$ 468,076
Gross Profit:
Gross profit	71,918	58,568	132,981	106,705
Operating income (loss)
Operating income (loss)	20,619	15,823	29,753	22,641
United States [Member]
Revenues:
Revenues	227,618	155,444	438,248	294,191
Gross Profit:
Gross profit	50,891	38,055	92,284	67,168
Operating income (loss)
Operating income (loss)	11,693	7,231	14,089	7,126
Canada [Member]
Revenues:
Revenues	42,212	35,752	84,075	75,146
Gross Profit:
Gross profit	9,934	8,100	18,996	17,402
Operating income (loss)
Operating income (loss)	6,129	4,477	11,552	10,225
Europe [Member]
Revenues:
Revenues	21,175	22,337	43,791	44,987
Gross Profit:
Gross profit	4,543	5,680	9,301	10,684
Operating income (loss)
Operating income (loss)	851	1,955	1,378	2,823
Other foreign [Member]
Revenues:
Revenues	31,863	28,567	62,988	53,752
Gross Profit:
Gross profit	6,550	6,733	12,400	11,451
Operating income (loss)
Operating income (loss)	$ 1,946	$ 2,160	$ 2,734	$ 2,467