Non-interest Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Non-interest income	$ 56,350	$ 51,835	$ 110,665	$ 103,321
Other revenues	17,037	16,866	29,768	37,218
Total non-interest income	73,387	68,701	140,433	140,539
Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	19,999	20,252	39,938	40,370
Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	13,983	12,524	27,419	24,676
Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	10,833	10,041	21,032	19,885
Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	8,900	7,210	17,596	14,436
Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	1,879	1,060	3,092	2,364
Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	756	748	1,588	1,590
Community Banking
Disaggregation of Revenue [Line Items]
Non-interest income	5,939	5,862	11,824	11,852
Other revenues	3,390	2,993	5,841	4,641
Total non-interest income	9,329	8,855	17,665	16,493
Community Banking | Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	5,724	5,644	11,404	11,415
Community Banking | Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Community Banking | Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	215	218	420	437
Community Banking | Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Community Banking | Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Community Banking | Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Corporate Banking
Disaggregation of Revenue [Line Items]
Non-interest income	453	428	985	887
Other revenues	1,848	2,758	3,581	4,376
Total non-interest income	2,301	3,186	4,566	5,263
Corporate Banking | Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	453	428	985	887
Corporate Banking | Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Corporate Banking | Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Corporate Banking | Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Corporate Banking | Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Corporate Banking | Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Retail Banking
Disaggregation of Revenue [Line Items]
Non-interest income	24,188	23,842	48,163	47,478
Other revenues	1,713	1,618	3,242	3,183
Total non-interest income	25,901	25,460	51,405	50,661
Retail Banking | Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	13,096	13,533	26,518	26,970
Retail Banking | Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Retail Banking | Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	10,618	9,823	20,612	19,448
Retail Banking | Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Retail Banking | Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Retail Banking | Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	474	486	1,033	1,060
Financial Management Services
Disaggregation of Revenue [Line Items]
Non-interest income	24,762	20,794	48,107	41,476
Other revenues	5,565	6,816	11,408	13,413
Total non-interest income	30,327	27,610	59,515	54,889
Financial Management Services | Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Financial Management Services | Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	13,983	12,524	27,419	24,676
Financial Management Services | Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Financial Management Services | Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	8,900	7,210	17,596	14,436
Financial Management Services | Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	1,879	1,060	3,092	2,364
Financial Management Services | Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Other
Disaggregation of Revenue [Line Items]
Non-interest income	1,008	909	1,586	1,628
Other revenues	4,521	2,681	5,696	11,605
Total non-interest income	5,529	3,590	7,282	13,233
Other | Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	726	647	1,031	1,098
Other | Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Other | Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Other | Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Other | Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Other | Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	$ 282	$ 262	$ 555	$ 530