Derivative Financial Instruments - Summary of Outstanding Foreign Currency Forward Contracts (Details) - Foreign Currency Forward Contracts - Cash Flow Hedges - Non-designated	3 Months Ended	12 Months Ended
	Mar. 31, 2019 USD ($) € / £ € / $ £ / $ $ / ¥ $ / ¥ $ / $	Dec. 31, 2018 USD ($) € / £ € / $ £ / $ $ / ¥ $ / ¥ $ / $
Derivative [Line Items]
Notional Amount	$ 111,536,000	$ 122,353,000
Derivative One
Derivative [Line Items]
Notional Amount	$ 1,014,000	$ 1,221,000
Effective Date	Mar. 31, 2019	Dec. 31, 2018
Maturity Date	May 31, 2019	Feb. 28, 2019
Index	EUR/GPB	EUR/GBP
Weighted Average Foreign Exchange Rate | € / £	0.8637	0.8981
Derivative Two
Derivative [Line Items]
Notional Amount	$ 3,014,000	$ 12,538,000
Effective Date	Mar. 31, 2019	Dec. 31, 2018
Maturity Date	May 31, 2019	Feb. 28, 2019
Index	EUR/USD	EUR/USD
Weighted Average Foreign Exchange Rate | € / $	1.1271	1.1479
Derivative Three
Derivative [Line Items]
Notional Amount	$ 8,241,000	$ 8,463,000
Effective Date	Mar. 31, 2019	Dec. 31, 2018
Maturity Date	May 31, 2019	Feb. 28, 2019
Index	GBP/USD	GBP/USD
Weighted Average Foreign Exchange Rate | £ / $	1.3038	1.2785
Derivative Four
Derivative [Line Items]
Notional Amount	$ 30,670,000	$ 44,946,000
Effective Date	Mar. 31, 2019	Dec. 31, 2018
Maturity Date	May 31, 2019	Feb. 28, 2019
Index	USD/CNY	USD/CNY
Weighted Average Foreign Exchange Rate | $ / ¥	6.7339	6.8738
Derivative Five
Derivative [Line Items]
Notional Amount	$ 617,000	$ 844,000
Effective Date	Mar. 31, 2019	Dec. 31, 2018
Maturity Date	May 31, 2019	Feb. 28, 2019
Index	USD/JPY	USD/JPY
Weighted Average Foreign Exchange Rate | $ / ¥	110.533	110.14
Derivative Six
Derivative [Line Items]
Notional Amount	$ 66,480,000	$ 54,041,000
Effective Date	Mar. 31, 2019	Dec. 31, 2018
Maturity Date	May 31, 2019	Feb. 28, 2019
Index	USD/TWD	USD/TWD
Weighted Average Foreign Exchange Rate | $ / $	30.78	30.559
Derivative Seven
Derivative [Line Items]
Notional Amount	$ 500,000	$ 300,000
Effective Date	Jan. 31, 2019	Dec. 31, 2018
Maturity Date	Oct. 31, 2019	Jan. 31, 2019
Index	USD/TWD	USD/TWD
Weighted Average Foreign Exchange Rate | $ / $	30.635	30.669
Derivative Eight
Derivative [Line Items]
Notional Amount	$ 500,000
Effective Date	Jan. 31, 2019
Maturity Date	Jan. 31, 2020
Index	USD/TWD
Weighted Average Foreign Exchange Rate | $ / $	30.635
Derivative Nine
Derivative [Line Items]
Notional Amount	$ 500,000
Effective Date	Jan. 31, 2019
Maturity Date	Nov. 30, 2019
Index	USD/TWD
Weighted Average Foreign Exchange Rate | $ / $	30.705