Stock Based Awards and Other Equity Instruments - Summary of MSU Activity (Parenthetical) (Details) - MSUs - shares		12 Months Ended
	Nov. 01, 2019	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
MSU's issued under incentive plan		133,000	[1]	121,000	[2],[3]	71,000	[4]
Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock awards vesting term		MSUs provide for vesting based upon the Company’s total shareholder return, or TSR, performance over the period commencing January 1, 2020 through December 31, 2022 relative to the TSR performance of the Nasdaq Composite Total Return Index.		MSUs which provide for vesting based upon the Company’s total shareholder return, or TSR, performance over the period commencing January 1, 2019 through December 31, 2021 relative to the TSR performance of the Nasdaq Composite Total Return Index.		MSUs provide for vesting based upon the Company’s total shareholder return, or TSR, performance over the period commencing January 1, 2018 through December 31, 2020 relative to the TSR performance of the Nasdaq Composite Total Return Index.
Performance measurement period start date		Jan. 01, 2020		Jan. 01, 2019		Jan. 01, 2018
Performance measurement period end date		Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Percentage of originally granted shares that may be earned upon performance achievement, maximum		200.00%		200.00%		200.00%
Percentage of originally granted shares that may be earned upon performance achievement, minimum		0.00%		0.00%		0.00%
MSU's issued under incentive plan				78,050
Employees | Dividend Equivalents
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
MSU's issued under incentive plan	42,477

[1] MSUs provide for vesting based upon the Company’s total shareholder return, or TSR, performance over the period commencing January 1, 2020 through December 31, 2022 relative to the TSR performance of the Nasdaq Composite Total Return Index. Based upon actual attainment relative to the target performance metric, the grantee has the ability to receive up to 200% of the target number of MSUs originally granted, or to receive none at all.

[2] Inclusive of 42,477 dividend equivalents issued to employees holding non-vested MSU grant awards in conjunction with our special cash dividend declared on November 1, 2019, which will be payable to the holder subject to, and only upon vesting of, the underlying awards.

[3] Inclusive of 78,050 MSUs which provide for vesting based upon the Company’s total shareholder return, or TSR, performance over the period commencing January 1, 2019 through December 31, 2021 relative to the TSR performance of the Nasdaq Composite Total Return Index. Based upon actual attainment relative to the target performance metric, the grantee has the ability to receive up to 200% of the target number of MSUs originally granted, or to be issued none at all.

[4] MSUs provide for vesting based upon the Company’s total shareholder return, or TSR, performance over the period commencing January 1, 2018 through December 31, 2020 relative to the TSR performance of the Nasdaq Composite Total Return Index. Based upon actual attainment relative to the target performance metric, the grantee has the ability to receive up to 200% of the target number of MSUs originally granted, or to be issued none at all.