Investment (Held-to-Maturity) Securities (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Sep. 30, 2011
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost	$ 676,047,000		$ 494,493,000
Investment Securities, Debt Maturities, Net Carrying Value	677,878,000	[1]	499,534,000	[2]
Investment Securities, Fair Value	687,127,000		528,458,000
Investment Securities, Gross Unrealized Gain	12,687,000	[3]	29,427,000	[3]
Investment Securities, Gross Unrealized Loss	(3,438,000)	[3]	(503,000)	[3]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Net Carrying Value	677,878,000	[1]	499,534,000	[2]
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Fair Value	687,127,000		528,458,000
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Nominal Yield	3.23%
Investment Securities, Pledged as Collateral [Abstract]
Investment Securities, Pledged as Collateral, Carrying Value	89,087,000		117,346,000
Investment Securities, Pledged as Collateral, Fair Value	91,804,000		121,647,000
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	139		67
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	192,538,000		93,649,000
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	53,850,000		0
Investment Securities, Continuous Unrealized Loss Position, Fair Value	246,388,000		93,649,000
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	2,526,000		503,000
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	912,000		0
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	3,438,000		503,000
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Carrying Value	50,182,000
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	51,864,000
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value	448,046,000
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value	454,710,000
Investment Securities, Portfolio Concentration Rated A to BBB, Carrying Value	20,784,000
Investment Securities, Portfolio Concentration Rated A to BBB, Fair Value	21,012,000
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Carrying Value	0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0
Investment Securities, Portfolio Concentration Not Rated, Carrying Value	158,866,000
Investment Securities, Portfolio Concentration Not Rated, Fair Value	159,541,000
Fixed Maturity Securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Debt Maturities, Net Carrying Value	627,696,000
Investment Securities, Fair Value	635,263,000
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Net Carrying Value	42,959,000
Investment Securities, Debt Maturities, One to Five Years, Net Carrying Value	341,494,000
Investment Securities, Debt Maturities, Six to Ten Years, Net Carrying Value	102,412,000
Investment Securities, Debt Maturities, Over Ten Years, Net Carrying Value	140,831,000
Investment Securities, Debt Maturities, Net Carrying Value	627,696,000
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Fair Value	43,136,000
Investment Securities, Debt Maturities, One to Five Years, Fair Value	341,970,000
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value	101,854,000
Investment Securities, Debt Maturities, Over Ten Years, Fair Value	148,303,000
Investment Securities, Fair Value	635,263,000
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Nominal Yield	3.16%
Investment Securities, Debt Maturities, One to Five Years, Nominal Yield	1.98%
Investment Securities, Debt Maturities, Six to Ten Years, Nominal Yield	3.79%
Investment Securities, Debt Maturities, Over Ten Years, Nominal Yield	5.84%
Investment Securities, Debt Maturities, Nominal Yield	3.27%
Investment Securities, Debt Maturities, Weighted Average Maturity	5.69	[4]
Municipal and other tax-exempt securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost	440,187,000		232,700,000
Investment Securities, Debt Maturities, Net Carrying Value	440,187,000		232,700,000
Investment Securities, Fair Value	439,870,000		235,940,000
Investment Securities, Gross Unrealized Gain	2,452,000	[3]	3,723,000	[3]
Investment Securities, Gross Unrealized Loss	(2,769,000)	[3]	(483,000)	[3]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Net Carrying Value	33,821,000
Investment Securities, Debt Maturities, One to Five Years, Net Carrying Value	308,451,000
Investment Securities, Debt Maturities, Six to Ten Years, Net Carrying Value	57,873,000
Investment Securities, Debt Maturities, Over Ten Years, Net Carrying Value	40,042,000
Investment Securities, Debt Maturities, Net Carrying Value	440,187,000		232,700,000
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Fair Value	33,996,000
Investment Securities, Debt Maturities, One to Five Years, Fair Value	308,701,000
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value	57,168,000
Investment Securities, Debt Maturities, Over Ten Years, Fair Value	40,005,000
Investment Securities, Fair Value	439,870,000		235,940,000
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Nominal Yield	2.91%	[5]
Investment Securities, Debt Maturities, One to Five Years, Nominal Yield	1.66%	[5]
Investment Securities, Debt Maturities, Six to Ten Years, Nominal Yield	2.65%	[5]
Investment Securities, Debt Maturities, Over Ten Years, Nominal Yield	4.75%	[5]
Investment Securities, Debt Maturities, Nominal Yield	2.23%	[5]
Investment Securities, Debt Maturities, Weighted Average Maturity	4.43	[4]
Investment Securities, Debt Maturities, Effective tax rate for nominal yield calculation	39.00%
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	107		53
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	166,382,000		92,768,000
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	53,073,000		0
Investment Securities, Continuous Unrealized Loss Position, Fair Value	219,455,000		92,768,000
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	1,921,000		483,000
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	848,000		0
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	2,769,000		483,000
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Carrying Value	0	[6]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[6]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value	280,583,000
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value	278,789,000
Investment Securities, Portfolio Concentration Rated A to BBB, Carrying Value	20,784,000
Investment Securities, Portfolio Concentration Rated A to BBB, Fair Value	21,012,000
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Carrying Value	0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0
Investment Securities, Portfolio Concentration Not Rated, Carrying Value	138,820,000
Investment Securities, Portfolio Concentration Not Rated, Fair Value	140,069,000
Other debt securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost	187,509,000		184,067,000
Investment Securities, Debt Maturities, Net Carrying Value	187,509,000		184,067,000
Investment Securities, Fair Value	195,393,000		206,575,000
Investment Securities, Gross Unrealized Gain	8,497,000	[3]	22,528,000	[3]
Investment Securities, Gross Unrealized Loss	(613,000)	[3]	(20,000)	[3]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Net Carrying Value	9,138,000
Investment Securities, Debt Maturities, One to Five Years, Net Carrying Value	33,043,000
Investment Securities, Debt Maturities, Six to Ten Years, Net Carrying Value	44,539,000
Investment Securities, Debt Maturities, Over Ten Years, Net Carrying Value	100,789,000
Investment Securities, Debt Maturities, Net Carrying Value	187,509,000		184,067,000
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Fair Value	9,140,000
Investment Securities, Debt Maturities, One to Five Years, Fair Value	33,269,000
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value	44,686,000
Investment Securities, Debt Maturities, Over Ten Years, Fair Value	108,298,000
Investment Securities, Fair Value	195,393,000		206,575,000
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Nominal Yield	4.08%
Investment Securities, Debt Maturities, One to Five Years, Nominal Yield	5.02%
Investment Securities, Debt Maturities, Six to Ten Years, Nominal Yield	5.27%
Investment Securities, Debt Maturities, Over Ten Years, Nominal Yield	6.27%
Investment Securities, Debt Maturities, Nominal Yield	5.71%
Investment Securities, Debt Maturities, Weighted Average Maturity	8.63	[4]
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	30		14
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	10,932,000		881,000
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	777,000		0
Investment Securities, Continuous Unrealized Loss Position, Fair Value	11,709,000		881,000
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	549,000		20,000
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	64,000		0
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	613,000		20,000
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Carrying Value	0	[6]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[6]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value	167,463,000
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value	175,921,000
Investment Securities, Portfolio Concentration Rated A to BBB, Carrying Value	0
Investment Securities, Portfolio Concentration Rated A to BBB, Fair Value	0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Carrying Value	0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0
Investment Securities, Portfolio Concentration Not Rated, Carrying Value	20,046,000
Investment Securities, Portfolio Concentration Not Rated, Fair Value	19,472,000
U.S. agency residential mortgage-backed securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Debt Maturities, Net Carrying Value	50,182,000		82,767,000
Investment Securities, Fair Value	51,864,000		85,943,000
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Net Carrying Value	50,182,000		82,767,000
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Fair Value	51,864,000		85,943,000
U.S. agency residential mortgage-backed securities [Member] | Other [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost	48,351,000		77,726,000
Investment Securities, Debt Maturities, Net Carrying Value	50,182,000
Investment Securities, Fair Value	51,864,000
Investment Securities, Gross Unrealized Gain	1,738,000	[3]	3,176,000	[3]
Investment Securities, Gross Unrealized Loss	(56,000)	[3]	0	[3]
Investments Securities, Transfers [Abstract]
Investment Securities, Transferred From Available For Sale Securities Portfolio, Fair Value					131,000,000
Investment Securities, Transferred From Available For Sale Securities Portfolio, Amortized Cost					118,000,000
Investment Securities, Transferred From Available For Sale Securities Portfolio, Net Unrealized Gain	1,800,000		5,000,000		13,000,000
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Net Carrying Value	50,182,000
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Fair Value	51,864,000
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Nominal Yield	2.73%	[7]
Investment Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities	3.1
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	2		0
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	15,224,000		0
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0		0
Investment Securities, Continuous Unrealized Loss Position, Fair Value	15,224,000		0
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	56,000		0
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0		0
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	56,000		0
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Carrying Value	50,182,000	[6]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	51,864,000	[6]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value	0
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value	0
Investment Securities, Portfolio Concentration Rated A to BBB, Carrying Value	0
Investment Securities, Portfolio Concentration Rated A to BBB, Fair Value	0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Carrying Value	0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0
Investment Securities, Portfolio Concentration Not Rated, Carrying Value	0
Investment Securities, Portfolio Concentration Not Rated, Fair Value	$ 0

[1] Carrying value includes $1.8 million of net unrealized gain which remains in Accumulated other comprehensive income (“AOCI”) in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.

[2] Carrying value includes $5.0 million of net unrealized gain which remains in AOCI in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.

[3] Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.

[4] Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalty.

[5] Calculated on a taxable equivalent basis using a 39% effective tax rate.

[6] U.S. government and government sponsored enterprises are not rated by the nationally-recognized rating agencies as these securities are guaranteed by agencies of the U.S. government or government-sponsored enterprises.

[7] The nominal yield on residential mortgage-backed securities is based upon prepayment assumptions at the purchase date. Actual yields earned may differ significantly based upon actual prepayments. See Quarterly Financial Summary - Unaudited for current yields on the investment securities portfolio.