CONSOLIDATED STATEMENTS OF STOCKHOLDERS' INVESTMENT (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended					12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012		Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		$ 1,504,372			$ 1,248,474	$ 1,504,372	$ 1,248,474	$ 1,204,068
Net income	92,952	103,343	256,392	[1]	106,500	415,904	593,804	431,612
Foreign currency translation adjustment						(1,275)	(230)	(2,690)
Dividends declared, $1.40 in 2013, $1.34 in 2012 and $1.20 in 2011 per share						(220,300)	(220,607)	(200,492)
Stock issued for acquisition							60,152
Stock issued for employee benefit plans						(34,978)	8,086	9,596
Issuance of restricted stock						0	0
Stock-based compensation expense						9,096	59,463	38,060
Excess tax benefit on deferred compensation and employee stock plans						27,209	12,294	15,255
Repurchase of common stock						(760,304)	(257,064)	(246,935)
Ending Balance	939,724		1,504,372			939,724	1,504,372	1,248,474
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance (in shares)		161,327,000			163,441,000	161,327,000	163,441,000	166,048,000
Beginning Balance		16,133			16,344	16,133	16,344	16,605
Stock issued for acquisition (in shares)							1,108,000
Stock issued for acquisition							111
Stock issued for employee benefit plans (in shares)						263,000	712,000	673,000
Stock issued for employee benefit plans						26	71	67
Issuance of restricted stock (in shares)						335,000	276,000	244,000
Issuance of restricted stock						34	28	24
Stock-based compensation expense (in shares)						30,000	28,000	16,000
Stock-based compensation expense						3	3	2
Repurchase of common stock (in shares)						(11,758,000)	(4,238,000)	(3,540,000)
Repurchase of common stock						(1,176)	(424)	(354)
Ending Balance (in shares)	150,197,000		161,327,000			150,197,000	161,327,000	163,441,000
Ending Balance	15,020		16,133			15,020	16,133	16,344
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		303,479			205,794	303,479	205,794	178,087
Stock issued for acquisition							60,041
Stock issued for employee benefit plans						(45,106)	(32,435)	(24,717)
Issuance of restricted stock						(34)	(28)	(24)
Stock-based compensation expense						7,346	57,813	37,193
Excess tax benefit on deferred compensation and employee stock plans						27,209	12,294	15,255
Repurchase of common stock						(75,000)
Ending Balance	217,894		303,479			217,894	303,479	205,794
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		2,218,229			1,845,032	2,218,229	1,845,032	1,613,912
Net income						415,904	593,804	431,612
Dividends declared, $1.40 in 2013, $1.34 in 2012 and $1.20 in 2011 per share						(220,300)	(220,607)	(200,492)
Ending Balance	2,413,833		2,218,229			2,413,833	2,218,229	1,845,032
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(9,345)			(9,115)	(9,345)	(9,115)	(6,425)
Foreign currency translation adjustment						(1,275)	(230)	(2,690)
Ending Balance	(10,620)		(9,345)			(10,620)	(9,345)	(9,115)
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(1,024,124)			(809,581)	(1,024,124)	(809,581)	(598,111)
Stock issued for employee benefit plans						10,102	40,450	34,246
Stock-based compensation expense						1,747	1,647	865
Repurchase of common stock						(684,128)	(256,640)	(246,581)
Ending Balance	$ (1,696,403)		$ (1,024,124)			$ (1,696,403)	$ (1,024,124)	$ (809,581)

[1] The Company's results for the fourth quarter of 2012 were effected by certain significant event-specific charges or credits related to our acquisitions and divestitures. See "Reported to Adjusted Statements of Operations Data" in Selected Financial Data in Item 6 and Management's Discussion and Analysis of Financial Condition and Results of Operations in Item 7 of Part II of this report.