Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Interest-bearing Deposit Liabilities [Abstract]
Interest bearing demand deposits	$ 4,377,407	$ 3,884,469
Money market accounts, excluding brokered deposits	7,042,350	5,971,629
Savings accounts	714,410	636,782
Time deposits, excluding brokered deposits	3,300,004	3,167,950
Brokered deposits	1,075,520	1,642,398
Total interest bearing deposits	16,509,691	15,303,228
Aggregate amount of time deposits of $100,000 or more	774,300	$ 703,300
Time Deposits, by Maturity [Abstract]
Maturing within one year	2,557,885
Between 1 — 2 years	794,081
2 — 3 years	401,324
3 — 4 years	105,103
4 — 5 years	177,968
Thereafter	23,159
Time deposits	$ 4,059,520