Business and Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Allowance for Doubtful Accounts Receivable [Roll Forward] | |||
| Beginning Balance | $ 46,946 | $ 35,690 | $ 34,861 |
| Accounts Written Off, net of Recoveries | (252,330) | (192,133) | (167,094) |
| Accounts Receivable Provision | 268,088 | 203,389 | 167,923 |
| Ending Balance | $ 62,704 | $ 46,946 | $ 35,690 |