Contractual interest rate for funds borrowed, under the debt agreement.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Long-Term Obligations and Notes Payable - Reliant Bank Revolver (Details)	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 15, 2019 USD ($)	Mar. 30, 2018 USD ($)	Mar. 30, 2018 CAD ($)
Debt Instrument [Line Items]
Long-term debt	$ 2,348,400,000	$ 2,067,100,000
Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity				$ 1,000,000,000.0	$ 50,000,000.0
Long-term debt	0	30,000,000.0
Unused credit commitments	$ 746,800,000
Revolving Credit Facility \| Line of Credit \| Reliant Bank Revolver
Debt Instrument [Line Items]
Interest rate, stated percentage	4.50%		4.75%
Line of credit facility, maximum borrowing capacity	$ 50,000,000.0		$ 30,000,000.0
Unused capacity, commitment fee percentage	0.50%
Long-term debt	$ 50,000,000.0	$ 50,000,000.0
Unused credit commitments	$ 0