Certain Balance Sheet Components (Schedule of Accounts Payable and Accrued Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accounts Payable And Accrued Liabilities Current [Abstract]
Accrued payroll and benefits	$ 16,702	$ 20,130
Accounts payable	14,471	12,073
Accrued interest	5,842	8,642
Accrued taxes	20,758	7,389
Operating lease liabilities	4,443
Other current liabilities	10,349	12,759
Total accounts payable and accrued liabilities	$ 72,565	$ 60,993