Organizational Efficiency Plan and Executive Severance (Schedule of Accrued Liabilities For Workforce Reduction Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 0	$ 0	$ 183
Employee termination and other charges	$ 3,792	1,489	1,147
Cash paid		(1,489)	(1,330)
Ending Balance		$ 0	$ 0

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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