Loans and Leases (Loans and Leases Outstanding) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Acquired	$ 1,109,933	$ 1,029,426
Originated	12,415,023	12,104,298
Total loans and leases	13,524,956	13,133,724
Commercial
Acquired	788,117	781,307
Originated	8,724,702	8,499,348
Commercial | Construction and land development
Acquired	80,827	78,915
Originated	342,021	319,847
Commercial | Mortgage
Acquired	637,481	642,891
Originated	6,367,096	6,362,490
Commercial | Commercial and industrial
Acquired	33,851	17,254
Originated	1,292,213	1,081,158
Commercial | Lease financing
Originated	413,422	381,763
Commercial | Other commercial real estate
Acquired	34,688	41,381
Originated	178,899	178,754
Commercial | Other
Acquired	1,270	866
Originated	131,051	175,336
Noncommerical
Acquired	321,816	248,119
Originated	3,690,321	3,604,950
Noncommerical | Mortgage
Acquired	270,688	213,851
Originated	1,071,089	982,421
Noncommerical | Construction and land development
Acquired	28,759	2,583
Originated	119,420	122,792
Noncommerical | Revolving mortgage
Acquired	20,129	30,834
Originated	2,122,675	2,113,285
Noncommerical | Consumer
Acquired	2,240	851
Originated	377,137	386,452
Loss Share Agreement [Member]
Acquired	816,300
Temecula Valley Bank [Member] | Loss Share Agreement [Member]
Acquired	195,400
Venture Bank [Member] | Loss Share Agreement [Member]
Acquired	$ 73,300