Equity Investees (Schedule of Operations for Equity Investees) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
INCOME STATEMENT DATA:
Revenues	$ 34,387	$ 27,250	$ 65,439	$ 56,194
Operating income	25,655	19,325	47,960	39,672
Net income	$ 23,295	$ 17,432	$ 43,145	$ 36,010

The amount of net income (loss) reported by an equity method investment of the entity.

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