Subsequent Events (Details) - Forward Swap	Feb. 13, 2018 USD ($) instrument	Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Oct. 31, 2015 USD ($)	May 31, 2014 USD ($)	Apr. 30, 2013 USD ($)
Subsequent Event [Line Items]
Notional amount		$ 250,000,000	$ 180,000,000	$ 300,000,000	$ 225,000,000	$ 240,000,000
Subsequent Event
Subsequent Event [Line Items]
Number of interest rate derivatives entered into | instrument	2
Notional amount	$ 250,000,000