Stock-Based Compensation - Additional Information (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]
Shares of common stock authorized for issuance	1,800,000
Remaining shares of common stock available for grant	495,658
Contractual life in years			6 years 6 months
Vesting period of stock options in years	3 years
The weighted-average grant-date fair value of stock options granted			$ 27.56
The weighted-average remaining contractual term for stock options outstanding	4 years 9 months 18 days	5 years 9 months 18 days
The weighted-average remaining contractual term for stock options vested and exercisable	4 years 8 months 12 days
The weighted-average remaining contractual term for stock options expected to vest	7 years 2 months 12 days
Aggregate intrinsic value of stock options outstanding	$ 34,200,000
Aggregate intrinsic value of stock options vested and exercisable	33,000,000
Aggregate intrinsic value of stock options expected to vest	1,200,000
The total grant-date fair value of stock options vested	200,000	1,200,000	100,000
The total intrinsic value of stock options exercised	5,100,000	9,200,000	900,000
Cash received from stock option exercises	570,000	2,636,000	1,345,000
Grant-date intrinsic value of RSU	$ 8.7
Weighted average remaining contractual life	1 year
Weighted-average grant-date fair value	$ 188.36	$ 81.47	$ 52.28
The total grant-date fair value of options vested	17,900,000	30,700,000	2,900,000
Cash used for employee withholding tax payments	7,500,000	11,500,000	700,000
Share settlement under RSUs	38,222	143,102	12,484
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized stock-based compensation expense	8,900,000	7,100,000
Weighted average remaining amortization periods	1 year	1 year 4 months 24 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life in years	10 years
Unamortized stock-based compensation expense	100,000	200,000
Weighted average remaining amortization periods	2 months 12 days	8 months 12 days
RSU and Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company granted performance contingent RSU	15,237	47,996
Stock-based compensation expense	1,100,000	1,700,000	1,300,000
Unamortized stock-based compensation expense	$ 2,100,000	$ 3,200,000
Minimum [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life in years	1 year
Maximum [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life in years	3 years