Note 18 - Unaudited Quarterly Financial Data (Detail) - Quarterly Financial Data (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
2012
Revenues	$ 3,090,567	$ 2,580,611	$ 1,497,927
Gross Profit	500,767	423,277	284,890
Operating income	114,200	97,338	41,667
Income before income taxes	101,183	90,177	36,304
Net income	62,455	55,213	31,282
Earnings per share:
Earnings per share, basic (in Dollars per share)	$ 1.62	$ 1.46	$ 0.84
Earnings per share, diluted (in Dollars per share)	$ 1.57	$ 1.42	$ 0.82
First Quarter [Member]
2012
Revenues	777,329	446,104
Gross Profit	128,260	82,390
Operating income	29,380	12,821
Income before income taxes	26,076	11,620
Net income	15,906	7,267
Earnings per share:
Earnings per share, basic (in Dollars per share)	$ 0.41	$ 0.19
Earnings per share, diluted (in Dollars per share)	$ 0.40	$ 0.19
Second Quarter [Member]
2012
Revenues	835,844	661,982
Gross Profit	129,636	105,510
Operating income	31,966	21,789
Income before income taxes	28,559	20,190
Net income	17,422	12,518
Earnings per share:
Earnings per share, basic (in Dollars per share)	$ 0.45	$ 0.33
Earnings per share, diluted (in Dollars per share)	$ 0.44	$ 0.32
Third Quarter [Member]
2012
Revenues	745,133	696,445
Gross Profit	125,171	113,788
Operating income	27,627	28,328
Income before income taxes	24,244	26,434
Net income	14,909	16,045
Earnings per share:
Earnings per share, basic (in Dollars per share)	$ 0.38	$ 0.42
Earnings per share, diluted (in Dollars per share)	$ 0.38	$ 0.41
Fourth Quarter [Member]
2012
Revenues	732,261	776,080
Gross Profit	117,700	121,589
Operating income	25,227	34,400
Income before income taxes	22,304	31,933
Net income	$ 14,218	$ 19,383
Earnings per share:
Earnings per share, basic (in Dollars per share)	$ 0.37	$ 0.51
Earnings per share, diluted (in Dollars per share)	$ 0.36	$ 0.50