Derivatives - Fair Value Measurements on Recurring Basis (Details) $ in Thousands	Dec. 31, 2018 USD ($)
2014 Swaps
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Asset, Fair Value	$ 751
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, Asset, Fair Value	0
2014 Swaps | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Asset, Fair Value	751
2014 Swaps | Fair Value, Measurements, Recurring | Unobservable Inputs (Level 3)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Asset, Fair Value	0
2015 Swaps
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Asset, Fair Value	5,893
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, Asset, Fair Value	0
2015 Swaps | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Asset, Fair Value	5,893
2015 Swaps | Fair Value, Measurements, Recurring | Unobservable Inputs (Level 3)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Asset, Fair Value	0
2018 Treasury Locks
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	(2,162)
2018 Treasury Locks | 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
2018 Treasury Locks | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	(2,162)
2018 Treasury Locks | Fair Value, Measurements, Recurring | Unobservable Inputs (Level 3)
Fair Value On Recurring Basis [Line Items]
Hedging Instrument, Liability, Fair Value	$ 0