Derivative Instruments, Foreign Exchange Contracts (Details) ¥ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018 EUR (€)	Dec. 31, 2017 EUR (€)	Dec. 31, 2017 JPY (¥)	Dec. 31, 2017 AUD ($)
Derivative [Abstract]
Expiration date of contract	Dec. 31, 2020
Foreign Exchange Contracts [Member]
Derivative [Abstract]
Foreign exchange contract outstanding	€ 3,200,000	€ 24,000	¥ 162.5	$ 0.2