Consolidated Statement Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Continuing Operations
Service revenues and sales	$ 354,170	$ 333,360	$ 707,113	$ 664,278
Cost of services provided and goods sold (excluding depreciation)	257,368	239,597	514,813	477,055
Selling, general and administrative expenses	49,770	50,424	102,937	106,078
Depreciation	6,380	6,358	12,621	12,646
Amortization	1,127	1,139	2,240	2,109
Total costs and expenses	314,645	297,518	632,611	597,888
Income from operations	39,525	35,842	74,502	66,390
Interest expense	(3,672)	(3,461)	(7,289)	(6,705)
Other income/(expense)- net	(970)	714	1,125	2,816
Income before income taxes	34,883	33,095	68,338	62,501
Income taxes	(13,609)	(12,809)	(26,619)	(24,114)
Net income	$ 21,274	$ 20,286	$ 41,719	$ 38,387
Earnings Per Share
Net income	$ 1.12	$ 0.96	$ 2.20	$ 1.82
Average number of shares outstanding	18,998	21,115	18,976	21,067
Diluted Earnings Per Share
Net income	$ 1.10	$ 0.94	$ 2.16	$ 1.78
Average number of shares outstanding	19,369	21,637	19,357	21,586
Cash Dividends Per Share	$ 0.16	$ 0.14	$ 0.32	$ 0.28