Goodwill and Identifiable Intangible Assets - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Line Items]
Goodwill from purchase of insurance book of business		$ 656,000
Impairment charge	$ 750,000	0	$ 0
Amortization expense of identifiable intangible assets	6,900,000	7,800,000	8,800,000
Impairment losses on identifiable intangible assets	0	0	0
Future amortization expense for identifiable intangible assets [Abstract]
2017	5,900,000
2018	4,900,000
2019	3,800,000
2020	2,500,000
2021	1,700,000
Insurance [Member]
Goodwill [Line Items]
Goodwill from purchase of insurance book of business		656,000
General Banking And Insurance [Member]
Goodwill [Line Items]
Impairment charge	$ 0	$ 0	$ 0