Business Combinations (Statement of Assets Acquired and Liabilities Assumed at Estimated Fair Values) (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended
	Apr. 18, 2014	Jul. 02, 2013	Dec. 31, 2014	Dec. 31, 2013
Fair value of liabilities assumed:
Goodwill			$ 1,786,225	$ 764,305
Sterling Financial Corporation [Member]
Fair value of consideration:
Cash payment 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 equivalents	253,067
Investment securities	1,378,300
Loans held for sale	214,911
Non-covered loans and leases, net	7,123,168
Premises and equipment	116,576
Residential mortgage servicing rights	62,770
Other intangible assets	54,562
Non-covered other real estate owned	8,666
Bank owned life insurance	193,246
Deferred tax asset	299,847
Accrued interest receivable	23,553
Other assets	148,906
Total assets acquired	9,877,572
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	85,319
Total liabilities assumed	8,767,025
Net assets acquired	1,110,547
Goodwill	1,021,920
Financial Pacific Holding Corp [Member]
Fair value of consideration:
Cash payment paid		156,110
Fair value of common shares issued		1,900
Total consideration		158,000
Fair value of assets acquired:
Cash and equivalents		6,452
Non-covered loans and leases, net		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