Mezzanine and Stockholders' Equity - Additional Information (Details) - USD ($)						12 Months Ended
	Sep. 11, 2019	Sep. 10, 2019	Dec. 08, 2017	Mar. 30, 2016	Oct. 14, 2015	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Stock issued during period new issues							$ 0
Number of shares holdback percentage			10.00%
Share-based compensation arrangement by based payment award outstanding (in shares)						725,864	607,346
Stock issued during period share conversion of notes (in shares)			520,081
Stock issued during period value conversion of notes			$ 5,400,000
Holdback shares not issued to former shareholders (in shares)						276,038
Warrants exercises in period (in shares)						1,247,644	177,405
Warrant issued during period value stock options exercised						$ 10,500,000	$ 1,700,000
Payments of ordinary dividends common stock						$ 51,319,000	$ 61,717,000	$ 17,759,000
Treasury stock, common, shares (in shares)						12,323,164	17,458,810
Allied Pacific of California Brokerage Account
Class of Stock [Line Items]
Treasury stock						$ 7,700,000	$ 7,300,000
Minimum
Class of Stock [Line Items]
Share-based compensation arrangement by share based payment award, warrant exercised, exercise price						$ 9.00	$ 9.00
Maximum
Class of Stock [Line Items]
Share-based compensation arrangement by share based payment award, warrant exercised, exercise price						$ 11.00	$ 11.00
Tranche one
Class of Stock [Line Items]
Share-based compensation arrangement by based payment award outstanding (in shares)							1,511,380	1,519,805
Warrant 1
Class of Stock [Line Items]
Exercise price per share (in dollars per share)			$ 11.00
Number of warrants (in shares)			850,000
Warrant 2
Class of Stock [Line Items]
Exercise price per share (in dollars per share)			$ 10.00
Number of warrants (in shares)			900,000
Private Placement
Class of Stock [Line Items]
Number of shares purchased by related party (in shares)					1,111,111
Stock issued during period new issues					$ 10,000,000.0
Exercise price per share (in dollars per share)				$ 10.00	$ 9.00
Former Shareholders of NMM
Class of Stock [Line Items]
Shares issued (in shares)						25,675,630
Series B Preferred Stock
Class of Stock [Line Items]
Number of shares purchased by related party (in shares)				555,555
Stock issued during period new issues				$ 5,000,000.0
Exercise price per share (in dollars per share)				$ 10.00
APC
Class of Stock [Line Items]
Interest costs incurred	$ 900,000
Payments of ordinary dividends common stock						$ 136,600,000	$ 60,000,000.0	$ 2,000,000.0
Treasury stock, common, shares (in shares)						12,323,164	17,290,317
AP-AMH | Affiliated Entity | Series A Preferred Stock
Class of Stock [Line Items]
Number of shares purchased by related party (in shares)	1,000,000
Stock issued during period new issues	$ 545,000,000.0
CDSC
Class of Stock [Line Items]
Payments of ordinary dividends common stock						$ 2,100,000	$ 2,600,000	2,000,000.0
AMG | APC
Class of Stock [Line Items]
Interest acquired		100.00%
Payments to acquire business		$ 1,200,000
Value of shares transferred in acquisition		$ 400,000
NMM
Class of Stock [Line Items]
Stock repurchased during period (in shares)			30,397,489
Number of shares holdback percentage						10.00%
Number of shares held back (in shares)			3,039,749
NMM | NMM
Class of Stock [Line Items]
Payments of ordinary dividends common stock						$ 0	$ 0	$ 13,800,000