Regulatory Capital Requirements (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital, Actual Amount	$ 760,349	$ 652,704
Total Capital (to risk-weighted assets), Ratio	14.68%	20.62%
Total Capital For Capital Adequacy Purposes, Amount	414,300	253,242
Total Capital (to risk-weighted assets), For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Tier 1 Capital, Actual Amount	695,489	612,584
Tier 1 Capital (to risk-weighted assets), Ratio	13.43%	19.35%
Tier 1 Capital For Capital Adequacy Purposes, Amount	207,150	126,621
Tier 1 Capital (to risk-weighted assets) For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Capital, Actual Amount	695,489	612,584
Tier 1 Capital (to average assets), Ratio	10.19%	12.78%
Tier 1 Capital For Capital Adequacy Purposes, Amount	272,891	191,778
Tier 1 Capital (to average assets) For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Parent Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital, Actual Amount	700,099	565,677
Total Capital (to risk-weighted assets), Ratio	13.52%	17.87%
Total Capital For Capital Adequacy Purposes, Amount	414,238	253,244
Total Capital (to risk-weighted assets), For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Total Capital To Be Well Capitalized Under Prompt Corrective Action Provision, Amount	517,797	316,556
Total Capital (to risk-weighted assets) To Be Well Capitalized Under Prompt Corrective Action Provision	10.00%	10.00%
Tier 1 Capital, Actual Amount	635,248	525,556
Tier 1 Capital (to risk-weighted assets), Ratio	12.27%	16.60%
Tier 1 Capital For Capital Adequacy Purposes, Amount	207,119	126,622
Tier 1 Capital (to risk-weighted assets) For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Capital To Be Well Capitalized Under Prompt Corrective Action Provision, Amount	310,678	189,933
Tier 1 Capital (to risk-weighted assets) To Be Well Capitalized Under Prompt Corrective Action Provision, Ratio	6.00%	6.00%
Tier 1 Capital, Actual Amount	635,248	525,556
Tier 1 Capital (to average assets), Ratio	9.29%	11.07%
Tier 1 Capital For Capital Adequacy Purposes, Amount	273,560	189,986
Tier 1 Capital (to average assets) For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Capital To Be Well Capitalized Under Prompt Corrective Provision, Amount	$ 341,950	$ 237,483
Tier 1 Capital (to average assets) To Be Well Capitalized Under Prompt Corrective Provision, Ratio	5.00%	5.00%