Business Combinations (Statement of Assets Acquired and Liabilities Assumed at Estimated Fair Values) (Details) - USD ($) $ in Thousands	Apr. 18, 2014	Jul. 02, 2013	Dec. 31, 2015	Dec. 31, 2014
Fair value of liabilities assumed:
Goodwill			$ 1,787,793	$ 1,786,225
Sterling Financial Corporation [Member]
Fair value of consideration:
Cash paid	$ 136,200
Liability recorded for warrants' cash payment per share	6,453
Fair value of common shares issued	1,939,497
Fair value of warrants, common stock options, and restricted stock exchanged	50,317
Total consideration	2,132,467
Fair value of assets acquired:
Cash and cash equivalents	253,067
Investment securities	1,378,300
Loans held for sale	214,911
Loans and leases	7,124,553
Premises and equipment	116,576
Residential mortgage servicing rights	62,770
Other intangible assets	54,562
Other real estate owned	8,666
Bank owned life insurance	193,246
Deferred tax asset	299,477
Accrued interest receivable	23,553
Other assets	148,906
Total assets acquired	9,878,587
Fair value of liabilities assumed:
Deposits	7,086,052
Securities sold under agreements to repurchase	584,746
Term debt	854,737
Junior subordinated debentures	156,171
Other liabilities	87,902
Total liabilities assumed	8,769,608
Net assets acquired	1,108,979
Goodwill	$ 1,023,488
Financial Pacific Holding Corp [Member]
Fair value of consideration:
Cash paid		$ 156,110
Fair value of common shares issued		1,900
Total consideration		158,000
Fair value of assets acquired:
Cash and cash equivalents		6,452
Loans and leases		264,336
Premises and equipment		491
Other assets		8,015
Total assets acquired		279,294
Fair value of liabilities assumed:
Term debt		211,204
Other liabilities		8,757
Total liabilities assumed		219,961
Net assets acquired		59,333
Goodwill		$ 96,777