Note 4 - Acquisitions (Detail) - Summary of the unaudited pro forma historical results (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Total revenues (in Dollars)	$ 764,870	$ 667,231
Income from operations (in Dollars)	$ 63,832	$ 51,001
Basic income per share	$ 3.30	$ 2.27
Diluted income per share	$ 3.25	$ 2.24