Debt Debt (Schedule of Interest Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Interest Expense [Abstract]
Interest expense	$ 45,789	$ 40,385	$ 36,197
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	164	2,627	3,928
Loss on Cash Flow Hedge Ineffectiveness	0	(353)	(18)
Capitalized interest	(212)	(510)	(549)
Charges taken on restructuring credit facility	0	583	0
Amortization of debt issuance costs and bond discount	3,314	3,592	3,514
Total interest expense	$ 49,055	$ 46,324	$ 43,108