Fair Value Measurements (Narratives) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Nonrecurring Basis | Level 3
Valuation of our interest rate swaps and impaired assets
Impaired long-lived assets	$ 2.1	$ 2.3
Impaired Long-Lived Assets
Valuation of our interest rate swaps and impaired assets
Weighted average disposal period of impaired assets	4 years