Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018	Jan. 01, 2017	Jan. 01, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Investment tax credit	$ 14,900,000	$ 11,500,000
Deferred tax asset, valuation allowance	10,506,000	2,892,000
Valuation allowance, deferred tax asset, increase (decrease)	7,600,000
Deferred tax assets, gross	352,038,000	238,601,000
Deferred tax assets, operating loss carryforwards, domestic		8,600,000
Deferred tax assets, operating loss carryforwards, state and local		6,800,000
Cumulative effect of adoption				$ 1,992,000	$ 2,996,000	$ 86,461,000
Retained earnings	229,391,000	202,734,000
Unrecognized tax benefits	647,000	1,525,000	$ 1,525,000				$ 1,525,000
Unrecognized tax benefits, interest and penalties	200,000	400,000
Income tax expense (benefit)	9,322,000	12,353,000	$ 56,263,000
Unrecognized tax benefits, period increase (decrease)	(600,000)
Retained Earnings (Accumulated Deficit)
Income Tax Contingency [Line Items]
Cumulative effect of adoption					2,996,000	$ 86,368,000
U.S. Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards	1,052,000,000
California
Income Tax Contingency [Line Items]
Income tax expense (benefit)	(1,100,000)
Net operating loss carryforwards	576,900,000
Other State
Income Tax Contingency [Line Items]
Net operating loss carryforwards	535,800,000
California Enterprise Zone Credits.
Income Tax Contingency [Line Items]
Investment tax credit	$ 1,000,000.0	$ 1,000,000
Accounting Standards Update 2016-16 | Retained Earnings (Accumulated Deficit)
Income Tax Contingency [Line Items]
Cumulative effect of adoption					300,000
Accounting Standards Update 2016-16 | Adjustment
Income Tax Contingency [Line Items]
Prepaid taxes					(378,500,000)
Deferred tax assets, gross					378,200,000
Accounting Standards Update 2016-09 | Deferred Tax Asset
Income Tax Contingency [Line Items]
Cumulative effect of adoption					3,300,000
Accounting Standards Update 2016-09 | Retained Earnings (Accumulated Deficit)
Income Tax Contingency [Line Items]
Cumulative effect of adoption					$ 3,300,000