Derivatives and Hedging Activities - Narrative (Details) - USD ($)		12 Months Ended
	Sep. 06, 2017	Dec. 31, 2018	Dec. 31, 2017	Sep. 22, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Payment to terminate existing interest rate swap contract	$ 1,100,000
Derivative liability, notional amount		$ 467,900,000	$ 433,000,000	$ 100,000,000
Derivative, fixed interest rate				1.94%
Hedge ineffectiveness		$ 0	$ 0