Debt (Details) - USD ($)			9 Months Ended
		Jan. 11, 2019	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Debt Instrument [Line Items]
Short-term debt			$ 138,249,000	$ 205,000,000	$ 132,000,000
Long-term debt
Current maturities of long-term debt			66,899,000	21,589,000	15,677,000
Finance lease liability	[1]		17,331,000	0	0
Total Current Maturities of Long-term Debt			66,899,000	21,589,000	15,677,000
Long-term debt, less current maturities			968,117,000	496,187,000	437,280,000
Finance lease liability	[1]		21,925,000	0	0
Total Long-term Debt, Less: Current Maturities			968,117,000	496,187,000	437,280,000
Nonrecourse
Debt Instrument [Line Items]
Short-term debt	[2]		35,278,000	0	0
Long-term debt
Current maturities of long-term debt	[3]		9,835,000	4,842,000	3,772,000
Long-term debt, less current maturities	[3]		242,895,000	146,353,000	77,114,000
Credit facility, maximum borrowing capacity			181,200,000
Total available for borrowings under lines of credit			146,000,000.0
Recourse
Debt Instrument [Line Items]
Short-term debt			102,971,000	205,000,000	132,000,000
Long-term debt
Current maturities of long-term debt	[4]		39,733,000	16,747,000	11,905,000
Long-term debt, less current maturities	[4]		703,297,000	$ 349,834,000	$ 360,166,000
LTG | LIBOR | Term Loan
Long-term debt
Borrowings under all lines of credit			$ 32,900,000
Interest rate			4.45%
Debt periodic payments			$ 600,000
Line of credit
Long-term debt
Credit facility, maximum borrowing capacity			1,628,700,000
Total available for borrowings under lines of credit			$ 1,207,700,000
Notes payable | LTG | LIBOR | 5-year term loan
Long-term debt
Interest rate			3.77%
Debt term		5 years	5 years
Term loan amount		$ 250,000,000
Notes payable | LTG | LIBOR | 7-year term loan
Long-term debt
Interest rate			4.02%
Debt term		7 years	7 years
Term loan amount		$ 250,000,000

[1] See Note 14, Leases, for additional information. September 30, 2019 balances include the former build-to-suit lease that was reclassed from other current liabilities and other long-term liabilities as a result of the adoption of ASC 842.

[2] In conjunction with the Lansing Trade Group ("LTG") acquisition, the Company assumed a revolving line of credit and a term loan with a syndicate of banks, which are non-recourse to the Company. The credit agreement provides the Company with a maximum availability of $181.2 million and had $146.0 million available for borrowing on this line of credit as of September 30, 2019. Any borrowings under the line of credit bear interest at variable rates, which are based on LIBOR or Bankers’ Acceptances plus an applicable spread. The maturity date for the revolving line of credit is June 26, 2023.

[3] In conjunction with the LTG acquisition, the Company also assumed a term loan with a syndicate of banks. The term loan had a balance of $32.9 million at September 30, 2019. Interest rates for the term loans were 4.45% as of September 30, 2019 and are based on LIBOR plus an applicable spread. Payments of $0.6 million are made on a quarterly basis.

[4] On January 11, 2019 the Company entered into a 5-year term loan in the amount of $250 million and a 7-year term loan of $250 million. A portion of the term loans were used to pay down debt assumed in the LTG acquisition. Interest rates are based on LIBOR plus an applicable spread. At September 30, 2019, the interest rates for the 5-year and 7-year term loan were 3.77% and 4.02%, respectively. Payments on the term loans will be made on a quarterly basis.