Allowance for Loan and Lease Losses (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) class	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) class	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Changes in allowance for loan losses
Balance at the beginning of the period	$ 57,258,000	$ 56,398,000	$ 56,739,000	$ 53,659,000
Charge-offs	(839,000)	(1,931,000)	(6,038,000)	(4,625,000)
Recoveries	319,000	332,000	1,100,000	1,671,000
(Credit) provision for loan and lease losses	2,154,000	1,673,000	7,091,000	5,767,000
Balance at the end of the period	58,892,000	56,472,000	58,892,000	56,472,000
Unfunded credit commitments liability included in other liabilities	1,300,000	1,400,000	1,300,000	1,400,000	$ 1,300,000
Credit commitments charged off against liability	0	0	0	0
Provision (credit) for loan and lease losses:
Total provision for loan and lease losses	2,154,000	1,673,000	7,091,000	5,767,000
Unfunded credit commitments	61,000	82,000	47,000	164,000
Total provision for credit losses	2,215,000	1,755,000	7,138,000	5,931,000
Total Loans and Leases	5,332,300,000		5,332,300,000		4,995,540,000
Allowance for loan and lease losses	6,270,000		6,270,000		3,638,000
Specific allowance for loan and lease losses	6,300,000		6,300,000		3,600,000
General allowance for loan and lease losses	52,600,000		52,600,000		53,100,000
Increase (decrease) in troubled debt restructurings			9,100,000
Troubled debt restructurings	32,000,000		32,000,000		22,900,000
Nonaccrual Loans and Leases	37,552,000		37,552,000		19,333,000
Increase in general portion of the allowance for loan and lease losses			(500,000)
Increase in specific portion of the allowance for loan and lease losses			2,700,000
Commercial Real Estate
Changes in allowance for loan losses
Balance at the beginning of the period	29,861,000	29,216,000	30,151,000	29,594,000
Charge-offs	(50,000)	0	(1,534,000)	(550,000)
Recoveries	0	0	0	0
(Credit) provision for loan and lease losses	(1,755,000)	1,845,000	(561,000)	2,017,000
Balance at the end of the period	28,056,000	31,061,000	28,056,000	31,061,000
Provision (credit) for loan and lease losses:
Total provision for loan and lease losses	$ (1,755,000)	1,845,000	$ (561,000)	2,017,000
Allowance for loan and lease losses, number of classes in portfolio | class	3		3
Total Loans and Leases	$ 2,883,428,000		$ 2,883,428,000		2,664,394,000
Commercial
Changes in allowance for loan losses
Balance at the beginning of the period	22,916,000	20,229,000	22,018,000	15,957,000
Charge-offs	(545,000)	(1,388,000)	(3,250,000)	(2,083,000)
Recoveries	170,000	112,000	495,000	418,000
(Credit) provision for loan and lease losses	3,923,000	2,009,000	7,201,000	6,670,000
Balance at the end of the period	26,464,000	20,962,000	26,464,000	20,962,000
Provision (credit) for loan and lease losses:
Total provision for loan and lease losses	$ 3,923,000	2,009,000	$ 7,201,000	6,670,000
Allowance for loan and lease losses, number of classes in portfolio | class	3		3
Total Loans and Leases	$ 1,470,866,000		$ 1,470,866,000		1,374,296,000
Indirect Automobile
Changes in allowance for loan losses
Balance at the beginning of the period	183,000	381,000	269,000	2,331,000
Charge-offs	(109,000)	(296,000)	(472,000)	(1,513,000)
Recoveries	102,000	179,000	467,000	1,170,000
(Credit) provision for loan and lease losses	(26,000)	57,000	(114,000)	(1,667,000)
Balance at the end of the period	150,000	321,000	150,000	321,000
Provision (credit) for loan and lease losses:
Total provision for loan and lease losses	(26,000)	57,000	(114,000)	(1,667,000)
Total Loans and Leases	7,607,000		7,607,000		13,678,000
Consumer
Changes in allowance for loan losses
Balance at the beginning of the period	4,298,000	4,012,000	4,301,000	3,359,000
Charge-offs	(135,000)	(247,000)	(782,000)	(479,000)
Recoveries	47,000	41,000	138,000	83,000
(Credit) provision for loan and lease losses	12,000	322,000	565,000	1,165,000
Balance at the end of the period	4,222,000	4,128,000	4,222,000	4,128,000
Provision (credit) for loan and lease losses:
Total provision for loan and lease losses	$ 12,000	322,000	$ 565,000	1,165,000
Allowance for loan and lease losses, number of classes in portfolio | class	4		4
Total Loans and Leases	$ 970,399,000		$ 970,399,000		943,172,000
Unallocated
Changes in allowance for loan losses
Balance at the beginning of the period	0	2,560,000	0	2,418,000
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
(Credit) provision for loan and lease losses	0	(2,560,000)	0	(2,418,000)
Balance at the end of the period	0	0	0	0
Provision (credit) for loan and lease losses:
Total provision for loan and lease losses	0	$ (2,560,000)	0	$ (2,418,000)
Taxi Medallion Portfolio
Provision (credit) for loan and lease losses:
Total Loans and Leases	36,000,000		36,000,000
Allowance for loan and lease losses	6,000,000		6,000,000
Specific allowance for loan and lease losses	4,700,000		4,700,000
General allowance for loan and lease losses	1,300,000		1,300,000		4,300,000
Increase (decrease) in troubled debt restructurings			8,800,000
Troubled debt restructurings	10,100,000		10,100,000		1,300,000
Nonaccrual Loans and Leases	$ 18,000,000		$ 18,000,000		$ 0