Derivatives - Summary of Designated Derivative Instruments Classified as Derivative Assets (Details) $ in Thousands	Mar. 31, 2019 USD ($) Instrument	Dec. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Market Value		$ 6,958	$ 590
Interest rate swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount	$ 1,416,025
Fair Market Value	$ (27,724)
Interest rate swaps | Interest rate swap, 9/20/2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	1
Hedge Interest Rates	2.69%
Notional Amount	$ 80,500
Fair Market Value	$ (437)
Interest rate swaps | Interest rate swap, 8/31/2022
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	1
Notional Amount	$ 13,179
Fair Market Value	$ 314
Interest rate swaps | Interest rate swap, 8/31/2022 | Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	1.27%
Interest rate swaps | Interest rate swap, 8/31/2022 | Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	1.29%
Interest rate swaps | Interest rate swap, 4/30/2024 - 10/31/2024
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	8
Notional Amount	$ 283,160
Fair Market Value	$ (384)
Interest rate swaps | Interest rate swap, 4/30/2024 - 10/31/2024 | Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	2.16%
Interest rate swaps | Interest rate swap, 4/30/2024 - 10/31/2024 | Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	2.39%
Interest rate swaps | Interest rate swap, 10/30/2026 - 10/31/2026
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	3
Notional Amount	$ 102,720
Fair Market Value	$ (3,631)
Interest rate swaps | Interest rate swap, 10/30/2026 - 10/31/2026 | Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	2.89%
Interest rate swaps | Interest rate swap, 10/30/2026 - 10/31/2026 | Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	3.08%
Interest rate swaps | Interest rate swap, 9/20/2027
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	1
Hedge Interest Rates	2.97%
Notional Amount	$ 30,023
Fair Market Value	$ (1,011)
Interest rate swaps | Interest rate swap, 3/20/2030 - 6/20/2030
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	2
Notional Amount	$ 160,401
Fair Market Value	$ 1,177
Interest rate swaps | Interest rate swap, 3/20/2030 - 6/20/2030 | Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	2.22%
Interest rate swaps | Interest rate swap, 3/20/2030 - 6/20/2030 | Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	2.57%
Interest rate swaps | Interest rate swap, 1/20/2031
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	1
Hedge Interest Rates	2.61%
Notional Amount	$ 9,899
Fair Market Value	$ (332)
Interest rate swaps | Interest rate swap, 4/30/3034
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	3
Hedge Interest Rates	2.78%
Notional Amount	$ 200,000
Fair Market Value	$ (6,545)
Interest rate swaps | Interest rate swap, 7/31/2035
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	5
Notional Amount	$ 151,610
Fair Market Value	$ (2,197)
Interest rate swaps | Interest rate swap, 7/31/2035 | Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	2.56%
Interest rate swaps | Interest rate swap, 7/31/2035 | Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	2.95%
Interest rate swaps | Interest rate swap, 10/31/2036
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	5
Notional Amount	$ 183,398
Fair Market Value	$ (2,710)
Interest rate swaps | Interest rate swap, 10/31/2036 | Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	2.62%
Interest rate swaps | Interest rate swap, 10/31/2036 | Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	2.95%
Interest rate swaps | Interest rate swap, 4/30/2037
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	3
Notional Amount	$ 100,000
Fair Market Value	$ (7,099)
Interest rate swaps | Interest rate swap, 4/30/2037 | Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	3.28%
Interest rate swaps | Interest rate swap, 4/30/2037 | Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	3.30%
Interest rate swaps | Interest rate swap, 1/31/2038
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Quantity | Instrument	3
Notional Amount	$ 101,135
Fair Market Value	$ (2,515)
Interest rate swaps | Interest rate swap, 1/31/2038 | Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	3.01%
Interest rate swaps | Interest rate swap, 1/31/2038 | Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedge Interest Rates	3.16%