Capital Stock - Common and Preferred Stock Authorized (Detail) - shares |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Class of Stock [Line Items] | ||
| Common stock, shares authorized | 500,000,000 | 500,000,000 |
| Series A Nonvoting Participating Preferred Stock [Member] | ||
| Class of Stock [Line Items] | ||
| Preferred stock, shares authorized | 20,000,000 | 20,000,000 |
| Series B Nonvoting Participating Preferred Stock [Member] | ||
| Class of Stock [Line Items] | ||
| Preferred stock, shares authorized | 150,000,000 | 150,000,000 |
| Series C Non-voting Participating Preferred Stock [Member] | ||
| Class of Stock [Line Items] | ||
| Preferred stock, shares authorized | 6,000,000 | 6,000,000 |
| Series D Nonvoting Participating Preferred Stock [Member] | ||
| Class of Stock [Line Items] | ||
| Preferred stock, shares authorized | 20,000,000 | 20,000,000 |