Senior Secured Notes and Subordinated Notes (Detail) - USD ($) $ in Thousands |
Sep. 30, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Senior Secured Notes | ||
| Debt Instrument [Line Items] | ||
| Fair Value | $ 3,244,579 | $ 6,448,352 |
| Subordinated Notes | ||
| Debt Instrument [Line Items] | ||
| Fair Value | 111,029 | 348,752 |
| Non-Consolidated Affiliates Senior Secured Notes | Senior Secured Notes | ||
| Debt Instrument [Line Items] | ||
| Borrowing Outstanding | 2,500 | |
| Fair Value | 2,504 | |
| Non-Consolidated Affiliates Senior Secured Notes | Subordinated Notes | ||
| Debt Instrument [Line Items] | ||
| Borrowing Outstanding | 10,000 | 24,200 |
| Fair Value | $ 8,851 | $ 14,377 |