Fair Value Of Financial Instruments (Narrative) (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)
Fair Value Disclosures [Abstract]
Transfers of financial assets from Level 2 to Level 1	$ 1,000,000	$ 1,100,000
Transfers of financial assets from Level 1 to Level 2	4,000,000	4,400,000
Transfers, Into Level 3		0
Transfers, out of Level 3, assets	$ 18,300,000	$ 18,300,000
Stated interest rate	4.25%	4.25%
Maturity date		Dec. 31, 2024