Consolidated Statement Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Consolidated Statement Of Income [Abstract]
Service revenues and sales	$ 358,300	$ 366,641
Cost of services provided and goods sold (excluding depreciation)	257,819	264,307
Selling, general and administrative expenses	55,671	55,560
Depreciation	7,149	6,795
Amortization	1,009	1,127
Total costs and expenses	321,648	327,789
Income from operations	36,652	38,852
Interest expense	(3,815)	(4,094)
Other income - net	816	1,706
Income before income taxes	33,653	36,464
Income taxes	(13,079)	(14,186)
Net income	$ 20,574	$ 22,278
Earnings Per Share
Net income	$ 1.17	$ 1.20
Average number of shares outstanding	17,510	18,522
Diluted Earnings Per Share
Net income	$ 1.12	$ 1.17
Average number of shares outstanding	18,305	19,000
Cash Dividends Per Share	$ 0.20	$ 0.18