Significant Accounting Policies - Schedule of Balances of Allowance for Doubtful Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||
Balance at beginning of period | $ 163,670 | $ 178,392 | $ 165,713 |
Additions: charges to bad debt expense | 94,290 | 102,877 | 109,342 |
Additions: charges to other accounts | 9,510 | 0 | 0 |
Deductions | (73,312) | (117,599) | (96,663) |
Balance at end of period | $ 194,158 | $ 163,670 | $ 178,392 |