Intangible Assets and Goodwill - Summary of Goodwill by Business Segment (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line Items]
Balance at beginning of period	$ 44,545
Acquisitions	417
Balance at end of period	44,962
Metropolitan Banks [Member]
Goodwill [Line Items]
Balance at beginning of period		8,078
Balance at end of period	8,078	8,078
Community Banks [Member]
Goodwill [Line Items]
Balance at beginning of period	30,553
Acquisitions	417
Balance at end of period	30,970
Other Financial Services [Member]
Goodwill [Line Items]
Balance at beginning of period		5,464
Balance at end of period	5,464	5,464
Executive, Operations & Support [Member]
Goodwill [Line Items]
Balance at beginning of period		450
Balance at end of period	$ 450	$ 450