Note F - Unaudited Condensed Pro Forma Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Revenue	$ 1,167,787	$ 1,067,511
Operating income	78,518	67,051
Net income	$ 42,461	$ 35,992
Basic earnings per share (in dollars per share)	$ 2.17	$ 1.82
Diluted earnings per share (in dollars per share)	$ 2.12	$ 1.78