Schedule II - Consolidated Valuation and Qualifying Accounts (Details 2) - Allowance for doubtful accounts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts:
Balance, beginning of period	$ 8,850	$ 8,069	$ 10,479
Charged to costs and expenses	7,864	7,532	7,024
Other	980	1,121	989
Deductions	9,197	7,872	10,423
Balance, end of period	$ 8,497	$ 8,850	$ 8,069