Derivative Instruments and Hedging Activities - Fair Value of Derivative Instruments Designated as Hedging Instruments (Details) - Derivatives Designated as Hedging Instruments - Interest rate swaps - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative asset, notional amount	$ 215,000,000
Derivative asset, fair value	194,000	$ 0
Derivative asset, notional amount	65,000,000
Derivative asset, fair value	0	108,000
Derivative liability, notional amount	150,000,000
Derivative liability, fair value	$ 0	$ 6,000