Covered Assets and FDIC Loss-sharing Asset (Analysis of Covered Loans) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Loans, net	$ 4,506,792	$ 4,444,842
Covered Loans [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	317,836	341,142
Valuation discount on covered loans	37,549	43,297
Allowance for loan losses	20,129	20,174	29,489	30,056
Loans, net	260,158	277,671
Commercial Portfolio Segment [Member] | Covered Loans [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	64,945	72,870
Real Estate Portfolio Segment [Member] | Covered Loans [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	203,032	212,521
One-to-Four Family Residential Construction [Domain] | Covered Loans [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	10,969	14,781
Commercial and Multifamily Residential Construction [Domain] | Covered Loans [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	6,349	6,869
Real Estate Construction Portfolio Segment [Member] | Covered Loans [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	17,318	21,650
Consumer Portfolio Segment [Member] | Covered Loans [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	32,541	34,101
One-to-Four Family Residential [Member] | Covered Loans [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	39,056	41,642
Commercial and Multifamily Residential [Member] | Covered Loans [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	$ 163,976	$ 170,879