Derivative Financial Instruments (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) contract	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) contract	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Derivative [Line Items]
Maximum Length of Time Hedged in Interest Rate Cash Flow Hedge			10 years
Reclassifications into Interest expense on cash flow hedge	$ 732,000,000	$ 30,000,000	$ 1,200,000	$ 183,000,000
Cash pledged to Peoples from counterparties	$ 0		$ 0		$ 0
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Number of Instruments Held | contract	17		17
Derivative, Notional Amount	$ 160,000,000.0		$ 160,000,000.0		160,000,000
Interest Rate Contract [Member]
Derivative [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	30,651,000		30,651,000		10,776,000
Other Assets [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Interest Rate Derivative Assets, at Fair Value	0		0		644,000
Liability [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	13,350,000		13,350,000		4,340,000
Interest Rate Swap [Member]
Derivative [Line Items]
Restricted Cash	$ 46,900,000		$ 46,900,000		$ 20,000,000.0