Leases (Tables)

3 Months Ended

Mar. 31, 2019

Leases [Abstract]

Additional Lease Information

Additional lease information is summarized below:

(Thousands of dollars)
	Three Months Ended
	March 31, 2019
Operating lease cost	$	112,105
Short-term lease cost	10,103
Variable lease cost	17,334
Operating cash outflows from operating leases	106,692
Weighted average remaining lease term for operating leases	6.1 years
Weighted average discount rate for operating leases	4.0		%

Maturities of Operating Lease Liabilities

The reconciliation excludes short-term leases that are not recorded on the balance sheet.

(Thousands of dollars)
	Operating Leases
Year Ending December 31,
2019 (excluding the three months ended March 31, 2019)	$	320,062
2020	393,077
2021	328,670
2022	265,871
2023	199,120
Thereafter	449,256
Total lease payments	1,956,056
Amount representing interest	(228,162		)
Present value of operating lease liabilities	$	1,727,894