FAIR VALUE, Level 3 Financial Assets and Liabilities, Roll Forward (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Percentage of instruments measured at fair value on a recurring basis
Instruments measured at fair value, percentage of assets (in hundredths)	8.20%	8.90%	8.20%	8.90%
Instruments measured at fair value, percentage of liabilities (in hundredths)	3.20%	3.90%	3.20%	3.90%
Instruments measured at fair value, level 3, percentage of assets (in hundredths)	15.40%	19.00%	15.40%	19.00%
Percentage Increase (decrease) of level 3 financial instruments from prior year period (in hundredths)	(4.00%)		(4.00%)
Payables-trade and other | Other liabilities
Changes in Level 3 recurring fair value measurements, liabilities [Roll Forward]
Fair value at beginning of period	$ (67)	$ (58)	$ (58)	$ (58)
Total gains (losses) for the period:
Included in earnings	0	0	0	0
Included in other comprehensive income	0	0	0	0
Purchases and contributions	0	0	(9)
Sales	0	0	0	0
Redemptions by issuer	0	0	0	0
Distributions	0	0	0	0
Transfers:
Into level 3	0	0	0	0
Out of level 3	0	0	0	0
Fair value at end of period	(67)	(58)	(67)	(58)
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets/liabilities) for assets/liabilities held at the end of the reporting period
Change in unrealized gains (losses) for the period included in earnings (or changes in net liabilities) for liabilities held at the end of the reporting period	0	0	0	0
Trading instruments | Corporate obligations
Changes in Level 3 recurring fair value measurements, assets [Roll Forward]
Fair value at beginning of period	189		156
Total gains (losses) for the period:
Included in earnings	(97)		(137)
Included in other comprehensive income	0		0
Purchases and contributions	2		75
Sales	(94)		(94)
Redemptions by issuer	0		0
Distributions	0		0
Transfers:
Into Level 3	0		0
Out of Level 3	0		0
Fair value at end of period	0		0
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets/liabilities) for assets/liabilities held at the end of the reporting period
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets) for assets held at the end of the reporting period	0		(40)
Trading instruments | Non-agency CMOs and ABS
Changes in Level 3 recurring fair value measurements, assets [Roll Forward]
Fair value at beginning of period	9	11	9	11
Total gains (losses) for the period:
Included in earnings	0	0	0	0
Included in other comprehensive income	0	0	0	0
Purchases and contributions	0	0	0	0
Sales	0	0	0	0
Redemptions by issuer	0	0	0	0
Distributions	(1)	(1)	(1)	(1)
Transfers:
Into Level 3	0	0	0	0
Out of Level 3	0	0	0	0
Fair value at end of period	8	10	8	10
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets/liabilities) for assets/liabilities held at the end of the reporting period
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets) for assets held at the end of the reporting period	0	0	1	0
Trading instruments | Equity securities
Changes in Level 3 recurring fair value measurements, assets [Roll Forward]
Fair value at beginning of period		14		44
Total gains (losses) for the period:
Included in earnings		0		5
Included in other comprehensive income		0		0
Purchases and contributions		0		20
Sales		0		0
Redemptions by issuer		0		0
Distributions		0		0
Transfers:
Into Level 3		0		0
Out of Level 3		0		(55)
Fair value at end of period		14		14
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets/liabilities) for assets/liabilities held at the end of the reporting period
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets) for assets held at the end of the reporting period		0		5
Trading instruments | Other
Changes in Level 3 recurring fair value measurements, assets [Roll Forward]
Fair value at beginning of period	1,964	5,264	1,986	2,309
Total gains (losses) for the period:
Included in earnings	(100)	(20)	(349)	(40)
Included in other comprehensive income	0	0	0	0
Purchases and contributions	19,470	11,358	38,487	23,333
Sales	(7,038)	(15,822)	(25,828)	(24,822)
Redemptions by issuer	0	0	0	0
Distributions	0	0	0	0
Transfers:
Into Level 3	0	0	0	0
Out of Level 3	0	0	0	0
Fair value at end of period	14,296	780	14,296	780
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets/liabilities) for assets/liabilities held at the end of the reporting period
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets) for assets held at the end of the reporting period	(60)	0	(71)	0
Available for sale securities | ARS municipal obligations
Changes in Level 3 recurring fair value measurements, assets [Roll Forward]
Fair value at beginning of period	27,480	85,814	28,015	86,696
Total gains (losses) for the period:
Included in earnings	133	2	133	2
Included in other comprehensive income	(583)	3,843	(1,118)	2,961
Purchases and contributions	0	0	0	0
Sales	(1,583)	(45)	(1,583)	(45)
Redemptions by issuer	(25)	0	(25)	0
Distributions	0	0	0	0
Transfers:
Into Level 3	0	0	0	0
Out of Level 3	0	0	0	0
Fair value at end of period	25,422	89,614	25,422	89,614
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets/liabilities) for assets/liabilities held at the end of the reporting period
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets) for assets held at the end of the reporting period	0	0	0	0
Available for sale securities | ARS - preferred securities
Changes in Level 3 recurring fair value measurements, assets [Roll Forward]
Fair value at beginning of period	102,899	112,955	110,749	114,039
Total gains (losses) for the period:
Included in earnings	0	25	0	25
Included in other comprehensive income	(300)	(282)	(8,150)	(1,366)
Purchases and contributions	0	0	0	0
Sales	0	0	0	0
Redemptions by issuer	0	(250)	0	(250)
Distributions	0	0	0	0
Transfers:
Into Level 3	0	0	0	0
Out of Level 3	0	0	0	0
Fair value at end of period	102,599	112,448	102,599	112,448
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets/liabilities) for assets/liabilities held at the end of the reporting period
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets) for assets held at the end of the reporting period	0	0	0	0
Private equity, other investments and other assets | Private equity investments
Changes in Level 3 recurring fair value measurements, assets [Roll Forward]
Fair value at beginning of period	207,523	208,674	209,088	211,666
Total gains (losses) for the period:
Included in earnings	4,269	14,414	4,440	17,060
Included in other comprehensive income	0	0	0	0
Purchases and contributions	2,407	2,241	6,961	6,343
Sales	0	0	(18)	0
Redemptions by issuer	0	0	0	0
Distributions	(9,801)	(4,385)	(16,073)	(14,125)
Transfers:
Into Level 3	0	0	0	0
Out of Level 3	0	0	0	0
Fair value at end of period	204,398	220,944	204,398	220,944
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets/liabilities) for assets/liabilities held at the end of the reporting period
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets) for assets held at the end of the reporting period	4,269	14,414	4,440	17,060
Valuation adjustments of certain private equity investments
Share of the net valuation adjustments gain		9,800		12,200
Noncontrolling interests' share of the net valuation adjustments gain		4,600		4,900
Private equity, other investments and other assets | Other investments
Changes in Level 3 recurring fair value measurements, assets [Roll Forward]
Fair value at beginning of period	493	1,564	565	1,731
Total gains (losses) for the period:
Included in earnings	18	41	11	81
Included in other comprehensive income	0	0	0	0
Purchases and contributions	0	0	0	0
Sales	0	0	0	0
Redemptions by issuer	(5)	(663)	(14)	(673)
Distributions	(67)	(26)	(123)	(223)
Transfers:
Into Level 3	0	0	0	0
Out of Level 3	0	0	0	0
Fair value at end of period	439	916	439	916
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets/liabilities) for assets/liabilities held at the end of the reporting period
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets) for assets held at the end of the reporting period	18	41	11	81
Private equity, other investments and other assets | Other assets
Changes in Level 3 recurring fair value measurements, assets [Roll Forward]
Fair value at beginning of period	1,526	2,407	4,975	787
Total gains (losses) for the period:
Included in earnings	1,586	(211)	(1,863)	1,409
Included in other comprehensive income	0	0	0	0
Purchases and contributions	0	0	0	0
Sales	0	0	0	0
Redemptions by issuer	0	0	0	0
Distributions	0	0	0	0
Transfers:
Into Level 3	0	0	0	0
Out of Level 3	0	0	0	0
Fair value at end of period	3,112	2,196	3,112	2,196
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets/liabilities) for assets/liabilities held at the end of the reporting period
Change in unrealized gains (losses) for the period included in earnings (or changes in net assets) for assets held at the end of the reporting period	$ 1,586	$ (211)	$ (1,863)	$ 1,409