Loans Covered loans loss share receivable (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Changes in Loss Share Receivable Associated with Covered Loans [Line Items]
Loans and Leases Receivable, Gross	$ 14,969,627	$ 14,143,423	$ 14,969,627	$ 14,143,423		$ 14,300,972
Covered impaired loan [Member]
Changes in Loss Share Receivable Associated with Covered Loans [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	637,600	915,400	637,600	915,400
Loss Share Receivable
Changes in Loss Share Receivable Associated with Covered Loans [Line Items]
Covered Loans and Leases Receivable Gross					54,748	61,827	95,593	113,734
Covered Loans and Leasses Receivable Accretion	(4,185)	(5,998)	(10,048)	(14,101)
Covered Loans and Leases Receivable Increase Due to Impairment	(3,897)	2,319	927	7,858
Covered Loans and Leases Receivable FDIC Reimbursement	(1,237)	(5,397)	(6,324)	(15,947)
Covered Loans and Leases Receivable Paid in Full	(1,448)	(2,607)	(2,401)	(7,634)
Covered Loans Loss Share Receivable	43,981	83,910	43,981	83,910
Covered Loans
Changes in Loss Share Receivable Associated with Covered Loans [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	$ 478,647	$ 760,436	$ 478,647	$ 760,436		$ 591,970