Quarterly report pursuant to Section 13 or 15(d)

Related Party Transactions (Details)

v3.20.1
Related Party Transactions (Details) - NSP China - Subsidiaries - USD ($)
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Dec. 31, 2019
Related Party Transaction [Line Items]      
Notes receivable, related parties, current $ 6,000,000.0   $ 6,000,000.0
Company's Joint Venture Partner      
Related Party Transaction [Line Items]      
Related party transaction, rate 3.00%    
Notes receivable, related parties, current $ 1,500,000   $ 1,500,000
Notes Receivable      
Related Party Transaction [Line Items]      
Related party transaction, amount $ 0 $ 0