Share Based Compensation (Schedule of Stock Options Exercise Price) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Options Outstanding	6,565
Exercise Price, Options Exercisable	2,666
1.20 - 2.308 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 1.20
Exercise Price, Maximum	$ 2.308
Exercise Price, Options Outstanding	11
Exercise Price, Options Exercisable	11
5.20 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 5.20
Exercise Price, Options Outstanding	547
Exercise Price, Options Exercisable	547
10.00 - 10.07 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 10.00
Exercise Price, Maximum	$ 10.070
Exercise Price, Options Outstanding	922
Exercise Price, Weighted Average Remaining Vesting Life in Years	0.15
Exercise Price, Options Exercisable	784
12.00 - 14.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 12.00
Exercise Price, Maximum	$ 14.000
Exercise Price, Options Outstanding	288
Exercise Price, Options Exercisable	288
18.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 18.00
Exercise Price, Options Outstanding	84
Exercise Price, Weighted Average Remaining Vesting Life in Years	0.96
Exercise Price, Options Exercisable	56
20.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 20.00
Exercise Price, Options Outstanding	360
Exercise Price, Weighted Average Remaining Vesting Life in Years	2.24
Exercise Price, Options Exercisable	112
23.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 23.00
Exercise Price, Options Outstanding	2,669
Exercise Price, Weighted Average Remaining Vesting Life in Years	2.35
Exercise Price, Options Exercisable	697
27.37-27.83 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 27.37
Exercise Price, Maximum	$ 27.830
Exercise Price, Options Outstanding	92
Exercise Price, Weighted Average Remaining Vesting Life in Years	2.82
Exercise Price, Options Exercisable	21
29.11-29.90 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 29.11
Exercise Price, Maximum	$ 29.900
Exercise Price, Options Outstanding	208
Exercise Price, Weighted Average Remaining Vesting Life in Years	2.10
Exercise Price, Options Exercisable	103
33.49-35.78 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 33.49
Exercise Price, Maximum	$ 35.780
Exercise Price, Options Outstanding	1,054
Exercise Price, Weighted Average Remaining Vesting Life in Years	3.36
Exercise Price, Options Exercisable	47
39.90-40.65 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 39.90
Exercise Price, Maximum	$ 40.650
Exercise Price, Options Outstanding	265
Exercise Price, Weighted Average Remaining Vesting Life in Years	3.34
47.63 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Minimum	$ 47.63
Exercise Price, Options Outstanding	65
Exercise Price, Weighted Average Remaining Vesting Life in Years	3.84