Stock-Based Compensation - Analysis of Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding-beginning of year	7,332,137	11,620,393	15,185,729
Options Exercised	(2,611,838)	(5,354,381)	(4,829,892)
Options Expired and forfeited	(85,406)	(6,600)	(73,425)
Adjustment to options for stock split - shares	0	0	(32)
Options Outstanding-end of year	5,719,468	7,332,137	11,620,393
Options Exercisable at end of year	2,930,368	4,261,817	8,265,818
Weighted Average Exercise Price Outstanding-beginning of year	$ 38.14	$ 35.42	$ 34.09
Options exercised in the period - weighted average exercise price	$ 37.45	$ 33.82	$ 33.67
Options expired and forfeited in the period - weighted average exercise price	$ 48.49	$ 44.63	$ 39.17
Adjustment due to stock split, Weighted Average Exercise Price	$ 0.00	$ 0.00	$ 32.96
Weighted Average Exercise Price Outstanding-end of year	$ 41.76	$ 38.14	$ 35.42
Weighted Average Exercise Price Exercisable at end of year	$ 34.42	$ 35.37	$ 36.28
7-year term [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	907,800	846,300	1,129,663
Options granted in the period- weighted average exercise price	$ 56.43	$ 46.10	$ 44.37
10-year term [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	176,775	226,425	208,350
Options granted in the period- weighted average exercise price	$ 56.10	$ 45.49	$ 44.40