Preferred Stock - Additional Information (Details)		1 Months Ended	3 Months Ended	12 Months Ended
		Dec. 31, 2020 USD ($) $ / shares shares	Mar. 31, 2016 Tranche	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($)
Class Of Stock [Line Items]
Number of tranches sold to investors | Tranche			2
Preferred Series A dividends payable				$ 21,800,000
Preferred stock dividend paid				$ 87,300,000	$ 91,700,000	$ 91,700,000
Accrued preferred dividends payable date				Feb. 14, 2022
Deemed dividends on Series A Preferred Stock					39,200,000	33,100,000
Preferred stock dividend per share | $ / shares				$ 23.75
Net carrying value of shares repurchased				$ 40,000,000.0	$ 91,500,000
Series A Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, liquidation per share | $ / shares		$ 1,000		$ 1,000	$ 1,000
Preferred stock, percentage of dividend				9.50%
Preferred stock dividend payment terms				fixed dividend payable quarterly 45 days after the end of each fiscal quarter
Preferred stock redemption premium percentage in sixth year				10.00%
Preferred stock redemption premium percentage in sixth year and thereafter				5.00%
Preferred stock redemption premium percentage in twelfth year				10.00%
Volume Weighted Average Share Price | $ / shares				$ 18.88
Preferred stock redemption premium percentage in twelfth year and thereafter				120.00%
Stock conversion, description				If the investors do not elect to convert their Series A Preferred into TRC common stock, Targa has a right after year twelve to force conversion, but only if the VWAP for the ten preceding trading days is greater than 120% of the conversion price
Preferred stock premium change in year four through six				10.00%
Preferred stock premium change in year six and thereafter				5.00%
Maximum number of common share would be issued upon conversion of preferred share | shares				44,260,953
Deemed dividends on Series A Preferred Stock	[1]				$ 39,200,000	$ 33,100,000
Repurchases of common stock (in shares) | shares		45,800
Preferred Stock, redemption price | $ / shares		$ 1,100			$ 1,100
Preferred Stock, liquidation preference multiplied percentage		110.00%			110.00%
Unpaid dividends		$ 1,100,000
Net carrying value of shares repurchased		$ 2,700,000
Series A Preferred Stock [Member] | Maximum [Member]
Class Of Stock [Line Items]
Incurrence of indebtedness other than stipulated fixed charge coverage				$ 2,750,000,000

[1] Includes $1.6 million attributable to the partial repurchase of Series A Preferred in December 2020. Refer to Note 11 – Preferred Stock.