Balance Sheet Components - Performance Awards Liability (Details) $ / shares in Units, $ in Millions		1 Months Ended
	Mar. 31, 2020 USD ($) $ / shares	Mar. 31, 2020 USD ($) $ / shares
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Performance based bonus compensation expense		$ 10.3
Unrecognized bonus compensation expense	$ 15.6	15.6
Employees
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Performance bonuses approved	25.3	25.3
Performance bonus, tranche one	8.0	8.0
Performance bonus, tranche two	$ 17.3	$ 17.3
Stock price threshold to earn bonus, tranche two (USD per share) | $ / shares	$ 21.39	$ 21.39
Unrecognized bonus compensation expense, period	1 month
Chief Executive Officer
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Performance bonuses approved	$ 8.1	$ 8.1
Stock price threshold to earn bonus, tranche two (USD per share) | $ / shares	$ 32.99	$ 32.99
Performance bonus, percent of amount, tranche one	50.00%	50.00%
Stock price threshold to earn bonus, tranche one (USD per share) | $ / shares	$ 31.61	$ 31.61
Performance bonus, percent of amount, tranche two	50.00%	50.00%
Unrecognized bonus compensation expense, period	1 year 5 months 4 days
Senior Executive
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Performance bonuses approved	$ 0.1	$ 0.1
Percent of bonus subject to performance condition	50.00%	50.00%
Two Board Of Director Members
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Performance bonuses approved	$ 0.3	$ 0.3
Minimum
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Stock price threshold to earn bonus (USD per share) | $ / shares	$ 25.80	$ 25.80
Maximum
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Stock price threshold to earn bonus (USD per share) | $ / shares	$ 32.99	$ 32.99
Accrued Liabilities
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Accrued bonuses	$ 10.3	$ 10.3
Long-Term Liabilities
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Accrued bonuses	$ 0.1	$ 0.1