Allowance for Loan Losses - Summary of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$ 60,996	$ 56,390
Charge-offs	(6,023)	(1,450)
Recoveries	787	1,634
Net Recoveries/(Charge-offs)	(5,236)	184
Provision for loan losses	5,649	2,472
Balance at End of Period	61,409	59,046
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	33,707	27,235
Charge-offs	(1)	0
Recoveries	122	49
Net Recoveries/(Charge-offs)	121	49
Provision for loan losses	1,075	3,679
Balance at End of Period	34,903	30,963
Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	11,596	8,966
Charge-offs	(5,477)	(829)
Recoveries	417	117
Net Recoveries/(Charge-offs)	(5,060)	(712)
Provision for loan losses	5,460	2,218
Balance at End of Period	11,996	10,472
Commercial construction
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	7,983	13,167
Charge-offs	0	0
Recoveries	0	1,129
Net Recoveries/(Charge-offs)	0	1,129
Provision for loan losses	(1,226)	(3,575)
Balance at End of Period	6,757	10,721
Consumer real estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	6,187	5,479
Charge-offs	(162)	(161)
Recoveries	148	238
Net Recoveries/(Charge-offs)	(14)	77
Provision for loan losses	5	(138)
Balance at End of Period	6,178	5,418
Other consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	1,523	1,543
Charge-offs	(383)	(460)
Recoveries	100	101
Net Recoveries/(Charge-offs)	(283)	(359)
Provision for loan losses	335	288
Balance at End of Period	$ 1,575	$ 1,472