Loans and Allowance for Loan Losses (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($) contract agreement	Sep. 30, 2015 USD ($) contract	Dec. 31, 2015 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 302,810		$ 159,713
TDRs both accruing and nonaccruing	56,300		13,100
Post-Modification outstanding recorded investment	$ 58,447	$ 687
Number of TDRs subsequently defaulted | contract	0	0
TDRs and loans impaired with minimum aggregate relationship balances	$ 1,000
Real estate acquired through foreclosure	$ 19,097		26,256
Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Period for which payments of principal and interest are past due	less than 90 days
Troubled Debt Restructurings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 48,200		8,800
Troubled Debt Restructurings [Member] | Loans With Extended Amortization Terms Or Other Payment Concessions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Post-Modification outstanding recorded investment	43,400	$ 700
Troubled Debt Restructurings [Member] | Loans With Significant Covenant Waivers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Post-Modification outstanding recorded investment	14,700
Troubled Debt Restructurings [Member] | Loans With Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Post-Modification outstanding recorded investment	$ 400	100
FDIC Loss Share Agreement [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loss share agreements | agreement	2
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 11,752		9,061
Post-Modification outstanding recorded investment		20
Real estate in process of foreclosure	9,200		7,400
Real estate acquired through foreclosure	4,500		9,300
Consumer [Member] | FDIC Loss Share Agreement [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real estate in process of foreclosure	2,800		4,100
Real estate acquired through foreclosure	$ 900		$ 1,600
Non-Single Family Portfolio [Member] | FDIC Loss Share Agreement [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recovery period	3 years
Percentage of recoveries on reimbursed losses due to FDIC	80.00%
Single Family Portfolio [Member] | FDIC Loss Share Agreement [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans covered by loss share agreement	$ 152,300	$ 177,500