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Other Postemployement Benefits (Details) - USD ($)
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]      
Maximum contribution match $ 6,000    
Defined Contribution Plan, Cost $ 700,000 $ 700,000 $ 1,000,000.0
Minimum [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Contribution Plan, Employer Matching Contribution, Percent of Match 100.00%