Segment Information (Reconciliation of Interest Expense from Segments to Consolidated) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Interest expense	$ 147,355	$ 146,025	$ 137,623
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Interest expense	$ 147,355	$ 146,025	$ 137,623