Loans and Leases (Loans and Leases Outstanding) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Acquired	$ 1,029,426	$ 1,809,235
Originated	12,104,298	11,576,115
Total loans and leases	13,133,724	13,385,350
Commercial
Acquired	781,307	1,450,035
Originated	8,499,348	7,994,495
Commercial | Construction and land development
Acquired	78,915	237,906
Originated	319,847	309,190
Commercial | Mortgage
Acquired	642,891	1,054,473
Originated	6,362,490	6,029,435
Commercial | Commercial and industrial
Acquired	17,254	49,463
Originated	1,081,158	1,038,530
Commercial | Lease financing
Originated	381,763	330,679
Commercial | Other commercial real estate
Acquired	41,381	107,119
Originated	178,754	160,980
Commercial | Other
Acquired	866	1,074
Originated	175,336	125,681
Noncommerical
Acquired	248,119	359,200
Originated	3,604,950	3,581,620
Noncommerical | Mortgage
Acquired	213,851	297,926
Originated	982,421	822,889
Noncommerical | Construction and land development
Acquired	2,583	20,793
Originated	122,792	131,992
Noncommerical | Revolving mortgage
Acquired	30,834	38,710
Originated	2,113,285	2,210,133
Noncommerical | Consumer
Acquired	851	1,771
Originated	$ 386,452	$ 416,606