Acquisitions (Narrative) (Details) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Mar. 06, 2015 USD ($) Location $ / shares shares	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Acquisition
Goodwill		$ 132,252		$ 132,252		$ 98,562
Non-interest expense related to acquisitions		9,700		9,700
Net loss on assets acquired		136	$ 187	1,239	$ 176
Salaries and Employee Benefit Costs
Acquisition
Non-interest expense related to acquisitions		4,400		4,400
Professional Fees
Acquisition
Non-interest expense related to acquisitions		1,700		1,700
Other Non-Interest Expenses
Acquisition
Non-interest expense related to acquisitions		3,600		3,600
NB&T Financial Group, Inc.
Acquisition
Total purchase price	$ 102,705
Outstanding shares | shares	3,442,329
Cash purchase price (in dollars per share) | $ / shares	$ 23.70
Number of common shares of Peoples issued for each common share of acquired company | shares	0.9319
Number of full service branches | Location	22
Deposits	$ 629,512
Decrease in cash		5,400
Decrease in loans		5,100
Increase in intangible assets		1,300
Increase in other assets		100
Decrease in accrued expenses and other liabilities		1,600
Decrease in net deferred tax asset		1,200
Increase in goodwill		7,600
Goodwill	$ 33,690	$ 33,700		33,700
Net loss on assets acquired				$ 600
NB&T Financial Group, Inc. | Cash Portion of Purchase Price
Acquisition
Cash purchase price (in dollars per share) | $ / shares	$ 7.75
NB&T Financial Group, Inc. | Loans
Acquisition
Loans acquired	$ 384,859