ALLL Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Allowance for loan and lease losses
Balance at beginning of period	$ 129,856	$ 130,729	$ 129,753	$ 130,351
Provision for loan losses	282	239	1,047	1,361
Charge-offs	(1,301)	(1,738)	(2,598)	(3,324)
Recoveries	1,682	1,406	2,317	2,248
Balance at end of period	130,519	130,636	130,519	130,636
Residential Real Estate
Allowance for loan and lease losses
Balance at beginning of period	15,131	14,066	14,680	14,067
Provision for loan losses	(258)	915	182	737
Charge-offs	(44)	(377)	(58)	(413)
Recoveries	21	20	46	233
Balance at end of period	14,850	14,624	14,850	14,624
Commercial Real Estate
Allowance for loan and lease losses
Balance at beginning of period	67,327	70,571	67,799	70,332
Provision for loan losses	491	(2,229)	205	(2,189)
Charge-offs	(303)	(83)	(748)	(264)
Recoveries	1,182	670	1,441	1,050
Balance at end of period	68,697	68,929	68,697	68,929
Other Commercial
Allowance for loan and lease losses
Balance at beginning of period	31,515	28,484	30,891	28,630
Provision for loan losses	532	1,334	1,644	2,267
Charge-offs	(675)	(586)	(1,369)	(1,749)
Recoveries	111	357	317	441
Balance at end of period	31,483	29,589	31,483	29,589
Home Equity
Allowance for loan and lease losses
Balance at beginning of period	9,519	9,426	9,963	9,299
Provision for loan losses	(559)	308	(1,018)	511
Charge-offs	(122)	(186)	(153)	(299)
Recoveries	108	177	154	214
Balance at end of period	8,946	9,725	8,946	9,725
Other Consumer
Allowance for loan and lease losses
Balance at beginning of period	6,364	8,182	6,420	8,023
Provision for loan losses	76	(89)	34	35
Charge-offs	(157)	(506)	(270)	(599)
Recoveries	260	182	359	310
Balance at end of period	$ 6,543	$ 7,769	$ 6,543	$ 7,769