CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Allowance for credit loss	$ 100,245	$ 56,367
Accumulated depreciation on property and equipment	$ 1,875,769	$ 1,815,844
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	296,543,000	294,319,000
Common stock, shares outstanding (in shares)	275,314,000	273,733,000
Treasury stock, shares held (in shares)	21,229,000	20,587,000
Customer Relationships
Accumulated amortization	$ 741,744	$ 735,367
Other Intangible Assets
Accumulated amortization	$ 684,491	$ 674,073