Derivatives - Fair Value Measurements on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
2014 Swaps
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	$ (333)	$ (1,478)
2014 Swaps | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	0	0
2014 Swaps | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	(333)	(1,478)
2014 Swaps | Fair Value, Measurements, Recurring | Unobservable Inputs (Level 3)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	0	0
2015 Swaps
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	(7,317)	(1,711)
2015 Swaps | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	0	0
2015 Swaps | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	(7,317)	(1,711)
2015 Swaps | Fair Value, Measurements, Recurring | Unobservable Inputs (Level 3)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	0	$ 0
2021 Swaps
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	(6,244)
2021 Swaps | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	0
2021 Swaps | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	(6,244)
2021 Swaps | Fair Value, Measurements, Recurring | Unobservable Inputs (Level 3)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	0
2020 Swap
Fair Value On Recurring Basis [Line Items]
Derivative Not Designated as Hedging Instrument, Liability, Fair Value	(106)
2020 Swap | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value On Recurring Basis [Line Items]
Derivative Not Designated as Hedging Instrument, Liability, Fair Value	0
2020 Swap | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value On Recurring Basis [Line Items]
Derivative Not Designated as Hedging Instrument, Liability, Fair Value	(106)
2020 Swap | Fair Value, Measurements, Recurring | Unobservable Inputs (Level 3)
Fair Value On Recurring Basis [Line Items]
Derivative Not Designated as Hedging Instrument, Liability, Fair Value	$ 0