Derivative Instruments - Summary of Gross Principal Notional Outstanding for CDS Contracts (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Ambac Rating
Notional outstanding	$ 2,776,103	$ 11,281,777
Predecessor Ambac [Member]
Ambac Rating
Notional outstanding		11,281,777
Successor Ambac [Member]
Ambac Rating
Notional outstanding	2,776,103
Other Derivatives [Member] \| Predecessor Ambac [Member]
Ambac Rating
Notional outstanding		11,281,777
Other Derivatives [Member] \| Predecessor Ambac [Member] \| AAA Rating [Member]
Ambac Rating
Notional outstanding		678,483
Other Derivatives [Member] \| Predecessor Ambac [Member] \| AA Rating [Member]
Ambac Rating
Notional outstanding		5,955,118
Other Derivatives [Member] \| Predecessor Ambac [Member] \| A Rating [Member]
Ambac Rating
Notional outstanding		3,684,193
Other Derivatives [Member] \| Predecessor Ambac [Member] \| BBB Rating [Member]
Ambac Rating
Notional outstanding		672,293
Other Derivatives [Member] \| Predecessor Ambac [Member] \| Below Investment Grade Rating [Member]
Ambac Rating
Notional outstanding		291,690
Other Derivatives [Member] \| Successor Ambac [Member]
Ambac Rating
Notional outstanding	2,776,103
Other Derivatives [Member] \| Successor Ambac [Member] \| AAA Rating [Member]
Ambac Rating
Notional outstanding	24,034
Other Derivatives [Member] \| Successor Ambac [Member] \| AA Rating [Member]
Ambac Rating
Notional outstanding	1,412,096
Other Derivatives [Member] \| Successor Ambac [Member] \| A Rating [Member]
Ambac Rating
Notional outstanding	235,917
Other Derivatives [Member] \| Successor Ambac [Member] \| BBB Rating [Member]
Ambac Rating
Notional outstanding	826,175
Other Derivatives [Member] \| Successor Ambac [Member] \| Below Investment Grade Rating [Member]
Ambac Rating
Notional outstanding	277,881
CLO [Member] \| Predecessor Ambac [Member]
Ambac Rating
Notional outstanding		6,155,767
CLO [Member] \| Successor Ambac [Member]
Ambac Rating
Notional outstanding	1,337,737
CLO [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member]
Ambac Rating
Notional outstanding		6,155,767
CLO [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member] \| AAA Rating [Member]
Ambac Rating
Notional outstanding		166,200
CLO [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member] \| AA Rating [Member]
Ambac Rating
Notional outstanding		4,676,362
CLO [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member] \| A Rating [Member]
Ambac Rating
Notional outstanding		1,313,205
CLO [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member] \| BBB Rating [Member]
Ambac Rating
Notional outstanding
CLO [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member] \| Below Investment Grade Rating [Member]
Ambac Rating
Notional outstanding
CLO [Member] \| Other Derivatives [Member] \| Successor Ambac [Member]
Ambac Rating
Notional outstanding	1,337,737
CLO [Member] \| Other Derivatives [Member] \| Successor Ambac [Member] \| AAA Rating [Member]
Ambac Rating
Notional outstanding
CLO [Member] \| Other Derivatives [Member] \| Successor Ambac [Member] \| AA Rating [Member]
Ambac Rating
Notional outstanding	1,209,071
CLO [Member] \| Other Derivatives [Member] \| Successor Ambac [Member] \| A Rating [Member]
Ambac Rating
Notional outstanding	128,666
Other [Member] \| Predecessor Ambac [Member]
Ambac Rating
Notional outstanding		5,126,010
Other [Member] \| Successor Ambac [Member]
Ambac Rating
Notional outstanding	1,438,366
Other [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member]
Ambac Rating
Notional outstanding		5,126,010
Other [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member] \| AAA Rating [Member]
Ambac Rating
Notional outstanding		512,283
Other [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member] \| AA Rating [Member]
Ambac Rating
Notional outstanding		1,278,756
Other [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member] \| A Rating [Member]
Ambac Rating
Notional outstanding		2,370,988
Other [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member] \| BBB Rating [Member]
Ambac Rating
Notional outstanding		672,293
Other [Member] \| Other Derivatives [Member] \| Predecessor Ambac [Member] \| Below Investment Grade Rating [Member]
Ambac Rating
Notional outstanding		291,690
Other [Member] \| Other Derivatives [Member] \| Successor Ambac [Member]
Ambac Rating
Notional outstanding	1,438,366
Other [Member] \| Other Derivatives [Member] \| Successor Ambac [Member] \| AAA Rating [Member]
Ambac Rating
Notional outstanding	24,034
Other [Member] \| Other Derivatives [Member] \| Successor Ambac [Member] \| AA Rating [Member]
Ambac Rating
Notional outstanding	203,025
Other [Member] \| Other Derivatives [Member] \| Successor Ambac [Member] \| A Rating [Member]
Ambac Rating
Notional outstanding	107,251
Other [Member] \| Other Derivatives [Member] \| Successor Ambac [Member] \| BBB Rating [Member]
Ambac Rating
Notional outstanding	826,175
Other [Member] \| Other Derivatives [Member] \| Successor Ambac [Member] \| Below Investment Grade Rating [Member]
Ambac Rating
Notional outstanding	$ 277,881