ALLL Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Allowance for loan and lease losses
Balance at beginning of period	$ 130,071	$ 129,856	$ 129,697	$ 129,753
Provision for loan losses	0	282	568	1,047
Charge-offs	(1,369)	(1,301)	(2,532)	(2,598)
Recoveries	3,684	1,682	4,653	2,317
Balance at end of period	132,386	130,519	132,386	130,519
Residential Real Estate | Residential Real Estate
Allowance for loan and lease losses
Balance at beginning of period	13,196	15,131	14,427	14,680
Provision for loan losses	699	(258)	(450)	182
Charge-offs	(255)	(44)	(355)	(58)
Recoveries	26	21	44	46
Balance at end of period	13,666	14,850	13,666	14,850
Commercial | Commercial Real Estate
Allowance for loan and lease losses
Balance at beginning of period	67,046	67,327	67,877	67,799
Provision for loan losses	(2,617)	491	(3,490)	205
Charge-offs	(34)	(303)	(287)	(748)
Recoveries	2,414	1,182	2,709	1,441
Balance at end of period	66,809	68,697	66,809	68,697
Commercial | Other Commercial
Allowance for loan and lease losses
Balance at beginning of period	36,054	31,515	32,525	30,891
Provision for loan losses	654	532	4,374	1,644
Charge-offs	(267)	(675)	(591)	(1,369)
Recoveries	590	111	723	317
Balance at end of period	37,031	31,483	37,031	31,483
Consumer and Other | Home Equity
Allowance for loan and lease losses
Balance at beginning of period	8,149	9,519	8,998	9,963
Provision for loan losses	447	(559)	(346)	(1,018)
Charge-offs	31	(122)	(198)	(153)
Recoveries	2	108	175	154
Balance at end of period	8,629	8,946	8,629	8,946
Consumer and Other | Other Consumer
Allowance for loan and lease losses
Balance at beginning of period	5,626	6,364	5,870	6,420
Provision for loan losses	817	76	480	34
Charge-offs	(844)	(157)	(1,101)	(270)
Recoveries	652	260	1,002	359
Balance at end of period	$ 6,251	$ 6,543	$ 6,251	$ 6,543