Employee Stock Compensation - Assumptions Used to Estimate the Value of Share-Based Awards (Detail)
|
3 Months Ended | 6 Months Ended | ||
---|---|---|---|---|
Jun. 30, 2013
|
Jun. 30, 2012
|
Jun. 30, 2013
|
Jun. 30, 2012
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Weighted average expected volatility | 40.00% | 44.00% | 40.00% | 43.00% |
Expected dividends | 0.00% | 4.82% | 4.82% | |
Minimum
|
||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Expected volatility | 18.00% | 37.00% | 18.00% | 37.00% |
Expected dividends | 0.00% | |||
Expected term (in years) | 3 months | 2 years | 3 months | 2 years |
Risk-free interest rate | 0.04% | 0.29% | 0.04% | 0.29% |
Maximum
|
||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Expected volatility | 44.00% | 49.00% | 47.00% | 49.00% |
Expected dividends | 5.45% | |||
Expected term (in years) | 6 years 4 months 24 days | 7 years | 6 years 4 months 24 days | 7 years |
Risk-free interest rate | 1.80% | 1.28% | 1.80% | 1.28% |