Accumulated Other Comprehensive Income - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reclassification out of Accumulated Other Comprehensive Income \| Accumulated other comprehensive income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest expense	$ 0.8	$ 0.7	$ 1.5	$ 1.4

Amount of the cost of borrowed funds accounted for as interest expense.

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Name:	us-gaap_InterestExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration