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		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:
Revenues	$ 307,665	$ 262,867	$ 775,741	$ 745,236
Gross Profit:
Gross profit	69,411	62,931	176,116	177,722
Operating income (loss)
Operating income (loss)	22,032	26,865	44,673	56,706
United States [Member]
Revenues:
Revenues	202,353	162,427	496,544	472,059
Gross Profit:
Gross profit	43,838	40,375	111,006	121,487
Operating income (loss)
Operating income (loss)	8,941	16,422	16,067	35,552
Canada [Member]
Revenues:
Revenues	56,026	47,141	131,172	130,900
Gross Profit:
Gross profit	14,351	13,352	31,753	33,995
Operating income (loss)
Operating income (loss)	10,397	9,069	20,622	20,928
Europe [Member]
Revenues:
Revenues	20,605	21,455	65,592	62,398
Gross Profit:
Gross profit	4,769	5,332	15,453	15,107
Operating income (loss)
Operating income (loss)	1,106	1,691	3,928	3,789
Other foreign [Member]
Revenues:
Revenues	28,681	31,844	82,433	79,879
Gross Profit:
Gross profit	6,453	3,872	17,904	7,133
Operating income (loss)
Operating income (loss)	$ 1,588	$ (317)	$ 4,056	$ (3,563)