Loans and Leases (Loans and Leases Outstanding) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Acquired	$ 1,270,818	$ 1,029,426
Originated	12,200,226	12,104,298
Total loans and leases	13,471,044	13,133,724
Commercial
Acquired	923,076	781,307
Originated	8,592,732	8,499,348
Commercial | Construction and land development
Acquired	106,670	78,915
Originated	335,271	319,847
Commercial | Mortgage
Acquired	728,872	642,891
Originated	6,330,843	6,362,490
Commercial | Commercial and industrial
Acquired	38,838	17,254
Originated	1,175,543	1,081,158
Commercial | Lease financing
Originated	394,268	381,763
Commercial | Other commercial real estate
Acquired	47,826	41,381
Originated	177,082	178,754
Commercial | Other
Acquired	870	866
Originated	179,725	175,336
Noncommerical
Acquired	347,742	248,119
Originated	3,607,494	3,604,950
Noncommerical | Mortgage
Acquired	291,254	213,851
Originated	1,030,032	982,421
Noncommerical | Construction and land development
Acquired	28,151	2,583
Originated	119,049	122,792
Noncommerical | Revolving mortgage
Acquired	25,776	30,834
Originated	2,091,000	2,113,285
Noncommerical | Consumer
Acquired	2,561	851
Originated	367,413	386,452
Loss Share Agreement [Member]
Acquired	$ 962,427