Covered Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013
Covered Assets [Line Items]
Covered assets	$ 277,343	$ 326,927
FDIC Indemnification Asset Movement Analysis [Roll Forward]
Balance at beginning of period	64,615	87,571
Additions	0	18,101
Payments made (received)	(1,295)	(13,421)
Amortization	(5,717)	(28,722)
Accretion, Carrying Amount of Loans	215	1,086
Balance at end of period	57,818	64,615
Acquired Impaired Assets [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period, AccretableYield	78,277	50,902
Balance at beginning of period, Carrying Amount of Loans	138,091	74,953
Additions, AccretableYield		43,299
Additions, Carrying Amount of Loans		107,946
Reclassification from nonaccretable balance, net, AccretableYield		17,850
Reclassification from nonaccretable balance, net, Carrying Amount of Loans		0
Accretion, AccretableYield	(7,862)	(33,774)
Transfers to REO, AccretableYield	0	0
Transfers to REO, Carrying Amount of Loans	(399)	(11,196)
Payments received, net, AccretableYield	0	0
Payments received, net, Carrying Amount of Loans	(39,402)	(67,386)
Balance at end of period, AccretableYield	70,415	78,277
Balance at end of period, Carrying Amount of Loans	106,152	138,091
FDIC Indemnification Asset Movement Analysis [Roll Forward]
Accretion, Carrying Amount of Loans	7,862	33,774
Acquired Non Impaired Assets [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period, AccretableYield	17,263	23,789
Balance at beginning of period, Carrying Amount of Loans	157,856	213,423
Additions, AccretableYield		0
Additions, Carrying Amount of Loans		0
Reclassification from nonaccretable balance, net, AccretableYield		0
Reclassification from nonaccretable balance, net, Carrying Amount of Loans		0
Accretion, AccretableYield	(1,347)	(6,526)
Transfers to REO, AccretableYield	0	0
Transfers to REO, Carrying Amount of Loans	0	0
Payments received, net, AccretableYield	0	0
Payments received, net, Carrying Amount of Loans	(12,662)	(62,093)
Balance at end of period, AccretableYield	15,916	17,263
Balance at end of period, Carrying Amount of Loans	146,541	157,856
FDIC Indemnification Asset Movement Analysis [Roll Forward]
Accretion, Carrying Amount of Loans	$ 1,347	$ 6,526