Derivative Financial Instruments Cross Currency Swap (Details) $ in Thousands, € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 01, 2016 EUR (€)	Dec. 01, 2016 AUD ($)
Currency Swap [Member]
Derivatives [Line Items]
Derivative, Notional Amount				€ 171.7	$ 248.9
Maturity Date	Jun. 30, 2019
Currency Swap 1 [Member]
Derivatives [Line Items]
Derivative, Notional Amount				85.5	123.9
Currency Swap 2 [Member]
Derivatives [Line Items]
Derivative, Notional Amount				€ 86.3	125.0
BBR Interest rate [Member] | Currency Swap 1 [Member]
Derivatives [Line Items]
Derivative, Description of Terms	Australian dollar BBR plus 4.50%
BBR Interest rate [Member] | Currency Swap 2 [Member]
Derivatives [Line Items]
Derivative, Description of Terms	Australian dollar BBR plus 4.50%
EURIBOR Interest Rate [Member] | Currency Swap 1 [Member]
Derivatives [Line Items]
Derivative, Description of Terms	EURIBOR plus 2.68%
EURIBOR Interest Rate [Member] | Currency Swap 2 [Member]
Derivatives [Line Items]
Derivative, Description of Terms	EURIBOR plus 2.90%
Intercompany Loan [Member]
Derivatives [Line Items]
Debt Instrument, Face Amount					$ 248.9
Other (expense)/income, net
Derivatives [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Net of Foreign Currency Transaction Gain (Loss) on Intercompany Loan	$ (5,679)	$ (2,451)	$ (3,267)