Off-Balance Sheet Arrangements, Commitments And Contingencies (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Certificates and other time deposits
1 year or less	$ 929,168
More than 1 year but less than 3 years	368,429
3 years or more but less than 5 years	42,813
Total	1,340,410	$ 1,365,449
Federal Home Loan Bank advances
1 year or less	215,796
Total	215,796
Subordinated Debentures
1 year or less	3,795
More than 1 year but less than 3 years	3,671
3 years or more but less than 5 years	8,650
5 years or more	81,375
Total	97,491
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
1 year or less	2,218
More than 1 year but less than 3 years	2,947
3 years or more but less than 5 years	2,014
Operating Leases, Future Minimum Payments, Due Thereafter	3,728
5 years or more	3,120
Total	10,299
Contractual obligations (other than securities sold under agreements to repurchase)
1 year or less	1,150,977
More than 1 year but less than 3 years	375,047
3 years or more but less than 5 years	53,477
5 years or more	84,495
Total	1,663,996
Interest payments on Federal Home Loan Bank advances to be paid over future periods.	796,000
Interest included in payments for subordinated debentures	$ 40,300