Stock-Based Compensation - Summary of Stock-Based Compensation Grants (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014
Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Awards Granted	1,562
Weighted-Average Grant Price Per Share	$ 78.15
Time Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Awards Granted	27,062
Weighted-Average Grant Price Per Share	$ 67.45
Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Awards Granted	21,338
Weighted-Average Grant Price Per Share	$ 67.43