Allowance for Credit Loss Statement - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Loss [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 559,419	$ 625,409	$ 636,659		$ 1,075,409	$ 1,303,079	$ 1,359,033	$ 1,391,500	$ (5,900)	$ 1,415,298
Accounts Receivable, Allowance for Credit Loss				$ 2,300	$ 7,500
Accounts Receivable [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 9,200