Financial Instruments and Fair Values - Summary of the Terms of Agreements and the Fair Value of Derivative Financial Instruments (Details) - Designated as Hedging Instrument - Cash Flow Hedging - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Asset	$ 0	$ 2,536,000
Liability	(22,895,000)	(5,243,000)
LIBOR | Interest Rate Swap, One Month LIBOR, 2.1485%
Derivatives, Fair Value [Line Items]
Notional Amount	$ 265,000,000
Pay Rate (as a percent)	2.1485%
Asset	$ 0	2,536,000
Liability	(4,449,000)	0
LIBOR | Interest Rate Swap, Three Month LIBOR, 2.9580%
Derivatives, Fair Value [Line Items]
Notional Amount	$ 125,000,000
Pay Rate (as a percent)	2.958%
Asset	$ 0	0
Liability	(9,223,000)	(2,623,000)
LIBOR | Interest Rate Swap, Three Month LIBOR, 2.9580%
Derivatives, Fair Value [Line Items]
Notional Amount	$ 125,000,000
Pay Rate (as a percent)	2.958%
Asset	$ 0	0
Liability	$ (9,223,000)	$ (2,620,000)