Reportable Business Segments and International Operations (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of segment operating income to consolidated income before income taxes
Segment operating income	$ 221,220	$ 215,670	$ 206,176	$ 185,279	$ 164,660	$ 186,059	$ 214,874	$ 186,085	$ 828,345	$ 751,678	$ 700,357
Interest expense									(59,613)	(43,029)	(40,741)
Stock-based compensation expense									(31,412)	(28,679)	(25,385)
Casualty loss related to flood					(8,600)	(12,800)				(21,479)
Change in contingent acquisition related obligations							17,800			17,813
Acquisition-related expenses	(2,000)				(2,000)				(2,000)	(2,000)
Income before income taxes									778,841	716,752	663,688
Total
Reconciliation of segment operating income to consolidated income before income taxes
Segment operating income									899,205	822,136	761,418
Unallocated amount to segment
Reconciliation of segment operating income to consolidated income before income taxes
Interest expense									(59,613)	(43,029)	(40,741)
Interest Income									11,512	10,245	5,046
Stock-based compensation expense									(31,412)	(28,679)	(25,385)
Casualty loss related to flood										(21,479)
Change in contingent acquisition related obligations										17,813
Acquisition-related expenses									(2,000)	(2,000)
Other costs, net									$ (38,851)	$ (38,255)	$ (36,650)