Stock-based Compensation - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2011
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Stock options, vesting period in years	3 years
Future compensation expense related to non-vested stock-based compensation arrangements	$ 9.9
Future compensation expense, weighted-average expected period of recognition in months	24 months
Performance Stock Units [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Performance stock unit granted in years	3 years	2 years
Number of vest performance stock unit, if performance criteria are not achieved	0
Minimum [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Percentage of target award the participants earn	0.00%
Maximum [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Percentage of target award the participants earn	150.00%
Restricted Stock Units (RSUs) [Member] | Performance Stock Units [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Stock options, vesting period in years	3 years
Restricted Stock Units [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Stock options, vesting period in years	1 year
Employee Stock Option [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Stock options, term in years	10 years