v2.4.0.8
Realized and Net Change in Unrealized Gains (Losses) on Financial Instruments on Financial Instruments on Which Fair Value Option was Elected (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Realized Gains (Losses) | Liabilities
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments $ (1,822) $ (2,833) $ (5,914) $ (2,833)
Realized Gains (Losses) | Assets
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments 7,710 (14,719) (47,140) 32,079
Realized Gains (Losses) | Corporate Bonds
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments 174 156 (2,012) 3,809
Realized Gains (Losses) | Senior Secured Notes
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments (1,822) (2,833) (5,914) (2,833)
Realized Gains (Losses) | Other
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments 7,620 280 20,914 1,706
Realized Gains (Losses) | Loans And Receivables
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments     0 43
Realized Gains (Losses) | Equity and Preferred Securities
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments (468) (622) (1,791) (2,020)
Realized Gains (Losses) | Corporate Loans
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments 384 (14,533) (64,251) 28,541
Net Change In Unrealized Gains (Losses) | Liabilities
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments (15,920) (108,706) (55,944) (322,650)
Net Change In Unrealized Gains (Losses) | Assets
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments (52,540) 87,908 25,580 118,111
Net Change In Unrealized Gains (Losses) | Corporate Bonds
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments (4,069) 1,262 (375) (4,596)
Net Change In Unrealized Gains (Losses) | Senior Secured Notes
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments (38,651) (127,864) (134,289) (419,817)
Net Change In Unrealized Gains (Losses) | Subordinated Notes
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments 22,731 19,158 78,345 97,167
Net Change In Unrealized Gains (Losses) | Other
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments (1,032) (4,075) 18,523 (2,963)
Net Change In Unrealized Gains (Losses) | Loans And Receivables
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments   (897) 0 (1,101)
Net Change In Unrealized Gains (Losses) | Equity and Preferred Securities
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments (5,870) 1,206 44 1,487
Net Change In Unrealized Gains (Losses) | Corporate Loans
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Realized and net change in unrealized gains (losses) on financial instruments $ (41,569) $ 90,412 $ 7,388 $ 125,284