CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 185,310	$ 151,323
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of intangible assets	1,300	187
Depreciation expense	34,995	36,323
Stock-based compensation expense-restricted stock and stock units	28,559	30,891
Excess tax benefits from stock-based compensation	(1,564)	(3,104)
Deferred income taxes	(23,540)	(19,544)
Provision for doubtful accounts receivable	6,173	7,657
Changes in assets and liabilities:
Increase in accounts receivable	(61,039)	(68,578)
Increase in accounts payable, accrued expenses, accrued payroll costs and retirement obligations	27,842	19,201
Increase in income taxes payable	11,015	37,019
Change in other assets, net of change in other liabilities	2,006	(121)
Net cash flows provided by operating activities	211,057	191,254
CASH FLOWS FROM INVESTING ACTIVITIES:
Payment for acquisitions, net of cash acquired		(1,525)
Capital expenditures	(32,117)	(35,816)
Increase in trusts for employee benefits and retirement plans	(38,479)	(5,752)
Net cash flows used in investing activities	(70,596)	(43,093)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repurchases of common stock	(106,782)	(117,468)
Cash dividends paid	(65,612)	(62,691)
Decrease in notes payable and other indebtedness	(4,430)	(76)
Excess tax benefits from stock-based compensation	1,564	3,104
Proceeds from exercises of stock options	29,895	37,843
Net cash flows used in financing activities	(145,365)	(139,288)
Effect of exchange rate changes on cash and cash equivalents	(2,984)	1,219
Net (decrease) increase in cash and cash equivalents	(7,888)	10,092
Cash and cash equivalents at beginning of period	287,635	279,336
Cash and cash equivalents at end of period	279,747	289,428
Non-cash items:
Stock repurchases awaiting settlement	$ 12,178	$ 11,639