Fair Value Measurements (Level 3 Valuation Techniques) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Fair Value Measurements, Recurring and nonrecurring, Valuation Techniques [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	$ 3,686	$ 13,624	$ 0	$ 0
Income Approach Valuation Technique
Fair Value Measurements, Recurring and nonrecurring, Valuation Techniques [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	$ 3,686
Income Approach Valuation Technique | Minimum
Fair Value Measurements, Recurring and nonrecurring, Valuation Techniques [Line Items]
Expected Volatility Range	12.30%
Income Approach Valuation Technique | Maximum
Fair Value Measurements, Recurring and nonrecurring, Valuation Techniques [Line Items]
Expected Volatility Range	30.50%