Stock-Based Compensation (Narrative) (Detail) - USD ($) $ / shares in Units, $ in Thousands			8 Months Ended	12 Months Ended
	Oct. 01, 2020	May 15, 2020	Aug. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized					15,000,000		26,200,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term				10 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value				$ 1,200
Proceeds from Stock Options Exercised			$ 461	$ 700	$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value				$ 0.78
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number				11,141,051
Allocated Share-based Compensation Expense, Net of Tax			$ 18,802		6,834	4,337
Aggregate intrinsic value, non-vested restricted stock				$ 9,000	$ 1,400	$ 2,100
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number				0	933,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				3,044,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 3.10	$ 3.62	$ 2.61
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Period Increase (Decrease), Weighted Average Exercise Price	$ 0.78	$ 0.58
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price				1.87
Common stock par value (in Dollars per Share)				$ 0.01	$ 0.01
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number				10,180,000	11,652,000
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period				630,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price				$ 2.78
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term				7 years 9 months 18 days	8 years 6 months
Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				3 years
Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				4 years
Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				1 year
Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				5 years
2005 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized				26,200,000
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				$ 0
Inducement Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period				961,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				240,200
Nonstatutory [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value, non-vested restricted stock				$ 300
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number				80,067