Share-Based Compensation (Details) (Employee Stock Option [Member], USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Employee Stock Option [Member]
Equity stock-based compensation
Term of options			10 years
Period of vesting			3 years
Assumptions used to measure the fair value of awards
Expected life			5 years 6 months	5 years 9 months 18 days
Risk-free interest rate (as a percent)			1.63%	1.11%
Expected volatility (as a percent)			30.28%	32.64%
Expected dividend yield (as a percent)			2.82%	1.57%
Stock option activity
Outstanding at the beginning of the period (in shares)			2,849
Granted (in shares)			715	416
Exercised (in shares)			(385)
Cancelled (in shares)			(40)
Outstanding at the end of the period (in shares)	3,139		3,139
Exercisable at the end of the period (in shares)	2,076		2,076
Share options, weighted average exercise price per share
Outstanding at the beginning of the period (in dollars per share)			$ 40.77
Granted (in dollars per share)			$ 59.65
Exercised (in dollars per share)			$ 33.75
Cancelled (in dollars per share)			$ 49.85
Outstanding at the end of the period (in dollars per share)	$ 45.81		$ 45.81
Exercisable at the end of the period (in dollars per share)	$ 38.21		$ 38.21
Share options, aggregate intrinsic value
Options outstanding average remaining contractual life			6 years 5 months 23 days
Options outstanding aggregate intrinsic value	$ 91,736,000		$ 91,736,000
Stock options exercisable average remaining contractual life			5 years 1 month 10 days
Stock options exercisable aggregate intrinsic value	76,462,000		76,462,000
Additional information pertaining to stock options
Cash received from exercise of stock options			13,000,000
Unrecognized compensation cost	13,000,000		13,000,000
Weighted-average period for amortization of unrecognized compensation cost			2 years 2 months 12 days
Weighted-average grant date fair value of stock options granted (in dollars per share)	$ 15.93		$ 12.99	$ 17.87
Total intrinsic value of stock options exercised	$ 12,148,000	$ 3,467,000	$ 14,923,000	$ 14,652,000