Derivative Instruments - Fair Values of Derivative Instruments on the Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Not Designated as Hedging Instrument | Other Assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	$ 115,623	$ 57,639
Not Designated as Hedging Instrument | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value, gross liability	0	0
Interest Rate Swap | Designated as Hedging Instrument | Other Assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	115,127	57,612
Interest Rate Swap | Designated as Hedging Instrument | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value, gross liability	0	0
Interest Rate Swap | Not Designated as Hedging Instrument | Other Assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	0	0
Interest Rate Swap | Not Designated as Hedging Instrument | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value, gross liability	0	0
Interest Rate Cap | Not Designated as Hedging Instrument | Other Assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset	496	27
Interest Rate Cap | Not Designated as Hedging Instrument | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value, gross liability	$ 0	$ 0