Intangible Assets - Summary of Goodwill by Business Segment (Detail) - USD ($)	6 Months Ended	9 Months Ended
	Jun. 30, 2015	Sep. 30, 2015
Goodwill [Line Items]
Balance at December 31, 2014	$ 44,962,000	$ 44,962,000
Impairment		(368,000)
Balance at September 30, 2015		44,594,000
Metropolitan Banks [Member]
Goodwill [Line Items]
Balance at December 31, 2014	8,078,000	8,078,000
Balance at September 30, 2015		8,078,000
Community Banks [Member]
Goodwill [Line Items]
Balance at December 31, 2014	30,970,000	30,970,000
Impairment	(368,000)	(368,000)
Balance at September 30, 2015		30,602,000
Other Financial Services [Member]
Goodwill [Line Items]
Balance at December 31, 2014	5,464,000	5,464,000
Balance at September 30, 2015		5,464,000
Executive, Operations & Support [Member]
Goodwill [Line Items]
Balance at December 31, 2014	$ 450,000	450,000
Balance at September 30, 2015		$ 450,000