Consolidated Variable Interest Entities - Number of FG VIE's Consolidated (Details) - Entity		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014
Number of FG VIEs Consolidated [Roll Forward]
Number of FG VIE's matured			(2)
Variable Interest Entity, Primary Beneficiary [Member]
Number of FG VIEs Consolidated [Roll Forward]
Number of FG VIE's consolidated, beginning of period		32	40
Number of FG VIE's acquired		4	0
Number of FG VIE's consolidated	[1]	1	1
Number of FG VIE's deconsolidated	[1]	0	(8)
Number of FG VIE's matured		0	(2)
Number of FG VIE's consolidated, end of period		37	31

[1] Net loss on consolidation was $26 million in Nine Months 2015, and net gain on deconsolidation was $120 million in Nine Months 2014, and recorded in “fair value gains (losses) on FG VIEs” in the consolidated statement of operations.