Derivative Financial Instruments - Schedule of Currency Forward Contracts CAD, EUR, GBP and SGD (Details) - Designated as Hedging Instrument - Foreign currency exchange contracts	Dec. 31, 2017 CAD	Dec. 31, 2017 EUR (€)	Dec. 31, 2017 GBP (£)	Dec. 31, 2017 SGD	Dec. 31, 2016 CAD	Dec. 31, 2016 EUR (€)	Dec. 31, 2016 GBP (£)	Dec. 31, 2016 SGD	Dec. 31, 2015 CAD	Dec. 31, 2015 EUR (€)	Dec. 31, 2015 GBP (£)	Dec. 31, 2015 SGD
Canadian Dollar
Derivative [Line Items]
Derivative notional amount | CAD	CAD 18,080,000				CAD 26,130,000				CAD 587,556
European Euro
Derivative [Line Items]
Derivative notional amount | €		€ 8,545,000				€ 11,261,848				€ 231,810
British Pound
Derivative [Line Items]
Derivative notional amount | £			£ 7,807,744				£ 4,191,763				£ 113,115
Singapore Dollar
Derivative [Line Items]
Derivative notional amount | SGD				SGD 1,765,000				SGD 4,375,000				SGD 0
Other expense — net | Canadian Dollar
Derivative [Line Items]
Derivative notional amount | CAD	CAD 0				CAD 0				CAD 1,117,850
Other expense — net | European Euro
Derivative [Line Items]
Derivative notional amount | €		€ 69,300,000				€ 16,000,000				€ 0
Other expense — net | British Pound
Derivative [Line Items]
Derivative notional amount | £			£ 14,912,019				£ 8,192,692				£ 0
Other expense — net | Singapore Dollar
Derivative [Line Items]
Derivative notional amount | SGD				SGD 28,127,000				SGD 0				SGD 0