Stockholders' Equity - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Feb. 29, 2016	Dec. 31, 2018	Dec. 31, 2017	Jul. 30, 2006	Dec. 23, 2004	Feb. 18, 2004
Class Of Stock [Line Items]
Number of options granted		0	0
Option Granted, Vesting period	3 years
Term of award	10 years
Stock-based compensation		$ 44,000	$ 148,000
Unrecognized compensation costs related to nonvested		0
Stock options exercised		0	0
Tax benefit from stock -based compensation expense		0	0
Cash payments received		$ 0	$ 0
Nonvested shares outstanding		25,000
2006 Omnibus Equity Compensation Plan
Class Of Stock [Line Items]
Omnibus Plan authorizes shares of Class A common stock for issuance, subject to adjustment in certain circumstances				350,000
Omnibus Plan provides that the maximum aggregate number of shares of Class A common stock units, stock awards and other stock-based awards that may be granted, other than dividend equivalent				100,000
Omnibus Plan expiration date		Jul. 17, 2016
Number of options granted		0
2006 Omnibus Equity Compensation Plan | Restricted Stock
Class Of Stock [Line Items]
Nonvested shares outstanding		0	0
2006 Omnibus Equity Compensation Plan | Minimum | Restricted Stock
Class Of Stock [Line Items]
Option Granted, Vesting period		2 years
2006 Omnibus Equity Compensation Plan | Maximum | Restricted Stock
Class Of Stock [Line Items]
Option Granted, Vesting period		5 years
1999 NQ Plan
Class Of Stock [Line Items]
Option Granted, Vesting period		4 years
Options granted vesting percentage		20.00%
1999 NQ Plan vesting rights		20% each year for the first four years from the date of grant.
1999 NQ Plan | Share-based Compensation Award, Tranche One
Class Of Stock [Line Items]
Options granted vesting percentage		20.00%
1999 NQ Plan | Share-based Compensation Award, Tranche Two
Class Of Stock [Line Items]
Options granted vesting percentage		20.00%
1999 NQ Plan | Share-based Compensation Award, Tranche Three
Class Of Stock [Line Items]
Options granted vesting percentage		20.00%
1999 NQ Plan | Share-based Compensation Award, Tranche Four
Class Of Stock [Line Items]
Options granted vesting percentage		20.00%
1999 ISO Plan
Class Of Stock [Line Items]
Shares reserve for issuance		300,000
Contractual life of option		10 years
1999 Stock Option Plans
Class Of Stock [Line Items]
Number of options granted		0
Series C convertible preferred stock
Class Of Stock [Line Items]
Preferred stock par value per share					$ 0.01
Common stock shares to be issued upon conversion of preferred stock					760,000
Liquidation preference per share		$ 0.01	$ 0.01
Series B Preferred Stock
Class Of Stock [Line Items]
Preferred stock par value per share						$ 0.01
Liquidation preference per share		$ 1,000				$ 1,000
Class A common stock
Class Of Stock [Line Items]
Common stock voting right		one vote per share
Number of options granted	75,000
Class A common stock | 1999 NQ Plan
Class Of Stock [Line Items]
Shares reserve for issuance		30,000
Class B common stock
Class Of Stock [Line Items]
Common stock voting right		ten votes per share