Deposits (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Deposits [Abstract]
FDIC Deposit Insurance Limit	$ 250,000
Time Deposits Greater than $250,000, Carrying Value	519,700,000	$ 590,600,000
Deposits, by Type [Abstract]
Demand	10,130,549,000	9,274,470,000
Checking With Interest	4,919,727,000	4,445,353,000
Money market accounts	8,193,392,000	8,205,705,000
Savings	2,099,579,000	1,909,021,000
Time	2,818,096,000	3,096,206,000
Total deposits	28,161,343,000	$ 26,930,755,000
Maturities of Time Deposits [Abstract]
2014	1,984,571,000
2015	435,823,000
2016	175,359,000
2017	154,294,000
2018	68,046,000
Thereafter	$ 3,000