ALLL Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Allowance for loan and lease losses
Balance at beginning of period	$ 129,226	$ 130,071	$ 129,572	$ 129,697
Provision for loan losses	3,013	0	4,611	568
Charge-offs	(4,589)	(1,369)	(8,818)	(2,532)
Recoveries	2,227	3,684	4,512	4,653
Balance at end of period	129,877	132,386	129,877	132,386
Residential Real Estate | Residential Real Estate
Allowance for loan and lease losses
Balance at beginning of period	11,535	13,196	12,436	14,427
Provision for loan losses	(10)	699	(936)	(450)
Charge-offs	(21)	(255)	(43)	(355)
Recoveries	18	26	65	44
Balance at end of period	11,522	13,666	11,522	13,666
Commercial | Commercial Real Estate
Allowance for loan and lease losses
Balance at beginning of period	64,753	67,046	65,773	67,877
Provision for loan losses	4,559	(2,617)	4,189	(3,490)
Charge-offs	(1,146)	(34)	(2,034)	(287)
Recoveries	337	2,414	575	2,709
Balance at end of period	68,503	66,809	68,503	66,809
Commercial | Other Commercial
Allowance for loan and lease losses
Balance at beginning of period	39,157	36,054	37,823	32,525
Provision for loan losses	(1,934)	717	(145)	4,440
Charge-offs	(650)	(386)	(1,481)	(726)
Recoveries	411	646	787	792
Balance at end of period	36,984	37,031	36,984	37,031
Consumer and Other | Home Equity
Allowance for loan and lease losses
Balance at beginning of period	7,679	8,149	7,572	8,998
Provision for loan losses	229	447	358	(346)
Charge-offs	(347)	31	(443)	(198)
Recoveries	101	2	175	175
Balance at end of period	7,662	8,629	7,662	8,629
Consumer and Other | Other Consumer
Allowance for loan and lease losses
Balance at beginning of period	6,102	5,626	5,968	5,870
Provision for loan losses	169	754	1,145	414
Charge-offs	(2,425)	(725)	(4,817)	(966)
Recoveries	1,360	596	2,910	933
Balance at end of period	$ 5,206	$ 6,251	$ 5,206	$ 6,251