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