Allowance for Loan Losses - Summary of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$ 55,351	$ 52,213	$ 52,775	$ 48,147
Charge-offs	(2,660)	(1,500)	(11,423)	(8,623)
Recoveries	1,171	564	2,459	1,890
Net (Charge-offs)/ Recoveries	(1,489)	(936)	(8,964)	(6,733)
Provision for loan losses	2,850	2,516	12,901	12,379
Balance at End of Period	56,712	53,793	56,712	53,793
Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	24,358	15,978	19,976	15,043
Charge-offs	(37)	(93)	(2,100)	(1,808)
Recoveries	182	264	415	662
Net (Charge-offs)/ Recoveries	145	171	(1,685)	(1,146)
Provision for loan losses	472	4,244	6,684	6,496
Balance at End of Period	24,975	20,393	24,975	20,393
Commercial and Industrial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	9,256	14,771	10,810	10,853
Charge-offs	(644)	(414)	(4,041)	(3,244)
Recoveries	243	169	499	589
Net (Charge-offs)/ Recoveries	(401)	(245)	(3,542)	(2,655)
Provision for loan losses	859	(2,232)	2,446	4,096
Balance at End of Period	9,714	12,294	9,714	12,294
Commercial Construction
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	13,944	11,701	13,999	12,625
Charge-offs	(1,453)	(163)	(2,097)	(1,108)
Recoveries	473	17	842	20
Net (Charge-offs)/ Recoveries	(980)	(146)	(1,255)	(1,088)
Provision for loan losses	1,951	1,356	2,171	1,374
Balance at End of Period	14,915	12,911	14,915	12,911
Consumer Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	5,803	8,418	6,095	8,400
Charge-offs	(101)	(369)	(1,957)	(891)
Recoveries	91	44	270	342
Net (Charge-offs)/ Recoveries	(10)	(325)	(1,687)	(549)
Provision for loan losses	(262)	(1,760)	1,123	(1,518)
Balance at End of Period	5,531	6,333	5,531	6,333
Other Consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	1,990	1,345	1,895	1,226
Charge-offs	(425)	(461)	(1,228)	(1,572)
Recoveries	182	70	433	277
Net (Charge-offs)/ Recoveries	(243)	(391)	(795)	(1,295)
Provision for loan losses	(170)	908	477	1,931
Balance at End of Period	$ 1,577	$ 1,862	$ 1,577	$ 1,862