Stock Incentive Plan - Summary of Assumptions Used in Monte Carlo Simulation Model (Detail)	3 Months Ended	6 Months Ended	1 Months Ended
Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	May 31, 2014 Market-based Restricted Stock Units [Member] Grant [Member]	Aug. 31, 2013 Market-based Restricted Stock Units [Member] Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.89%	1.48%		0.78%	0.62%
Volatility	55.00%	55.00%	55.00%	54.00%	54.00%

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(2)(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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