Derivative Financial Instruments - Summary of Derivative Positions (Details) - 12 months ended Dec. 31, 2018	GBP (£) $ / £ € / £	USD ($) $ / £ € / £
Interest Rate Swap
Derivative [Line Items]
Notional Amount | $		$ 211,640,625
Weighted Average Remaining Maturity In Years	4 years
Sell | USD/British Pound
Derivative [Line Items]
Notional Amount	£ 1,962,900
Weighted Average Remaining Maturity In Years	3 months 19 days
Average Exchange Rate | $ / £	1.28	1.28
Sell | EURO/British Pound
Derivative [Line Items]
Notional Amount	£ 2,568,300
Weighted Average Remaining Maturity In Years	3 months 19 days
Average Exchange Rate | € / £	1.11	1.11