Quarterly report pursuant to Section 13 or 15(d)

Fair Value Of Financial Instruments (Fair Value, Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation) (Detail)

v2.4.0.6
Fair Value Of Financial Instruments (Fair Value, Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation) (Detail) (USD $)
3 Months Ended 9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 30, 2011
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance $ (15,800,000) $ 0 $ (19,500,000) $ 0
Total losses        
Included in earnings 4,100,000 0 (11,700,000) 0
Included in other comprehensive income 0 0 0 0
Settlements 0 0 19,500,000 0
Transfers into Level 3 0 0 0 0
Transfers out of Level 3 0 0 0 0
Balance (11,700,000) 0 (11,700,000) 0
Total losses for the period included in earnings attributable to the change in unrealized losses on assets still held at the reporting date $ 4,100,000 $ 0 $ (11,700,000) $ 0