Investment in AllianceBernstein (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Investment in AllianceBernstein [Abstract]
Investment in AllianceBernstein, beginning of period	$ 1,560,536
Equity in net income attributable to AllianceBernstein Unitholders	42,997	32,707
Changes in accumulated other comprehensive income (loss)	(3,719)	802
Additional investments in AllianceBernstein from cash distributions paid to AllianceBernstein consolidated rabbi trust	5,929	864
Additional investments with proceeds from exercises of compensatory options to buy Holding Units, net	6,642	0
Cash distributions received from AllianceBernstein	(40,077)	(17,880)
Change in Holding Units held by AllianceBernstein for long-term incentive compensation plans	43,277
Investment in AllianceBernstein, end of period	$ 1,615,585

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

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+ Details

- Definition

Net of tax amount of other comprehensive income (loss) attributable to the parent entity.

+ References

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+ Details