Cash, Cash Equivalents, and Restricted Cash (Schedule of Cash, Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted Cash And Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 367,278	$ 308,560	$ 108,309
Restricted cash - current asset	65,561	31,671
Total cash, cash equivalents, and restricted cash	435,626	342,808	141,120	$ 178,300
Securitization Escrow Accounts [Member] | Restricted Cash - Current Asset [Member]
Restricted Cash And Cash Equivalents Items [Line Items]
Restricted cash - current asset	64,764	31,507	30,046
Payment and Performance Bonds [Member] | Restricted Cash - Current Asset [Member]
Restricted Cash And Cash Equivalents Items [Line Items]
Restricted cash - current asset	797	164	197
Surety Bonds and Workers Compensation [Member] | Other Assets - Noncurrent [Member]
Restricted Cash And Cash Equivalents Items [Line Items]
Restricted cash - noncurrent asset	$ 2,787	$ 2,577	$ 2,568