4. Leases

The following table summarizes the impact of the changes made to the January 1, 2019 consolidated balance sheet for the adoption of the new accounting standard pertaining to leases. The prior periods have not been restated and have been reported under the accounting standard in effect for those periods.


	Balance at		Impact of		Balance at
	December 31,		Lease Standard		January 1,
	2018				2019
Total assets	$	1,639,782	$	102,651	$	1,742,433
Total current liabilities		432,722		25,304		458,026
Total long-term liabilities		1,820,788		79,703		1,900,491

The increase in total assets and total liabilities at March 31, 2019 from December 31, 2018 was primarily due to the impact from the adoption of the new accounting standard pertaining to lease arrangements. See Note 2 for additional information on the impact of the adoption of this standard.

The Company determines if a contract is, or contains, a lease at contract inception. Operating leases are included in operating lease right-of-use ("ROU") assets, current portion of operating lease liabilities and operating lease liabilities, net of current portion in the Company's unaudited consolidated balance sheets. Finance leases are included in property and equipment, current portion of finance lease obligations and finance lease obligations, net of current portion in the Company's unaudited consolidated balance sheets.

ROU assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. In addition, ROU assets include initial direct costs incurred by the lessee as well as any lease payments made at or before the commencement date, and exclude lease incentives. As most of the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. Lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Leases with a term of one year or less are generally not included in ROU assets and liabilities.

Operating lease and finance lease ROU assets and operating lease and finance lease liabilities are recorded on the consolidated balance sheet as follows:


	March 31,
	2019
Balance sheet location:
Operating Lease
Operating lease right-of-use asset, net	$	100,727
Current portion of operating lease obligations		27,368
Operating lease right-of-use liability, net of current portion		78,290
Finance Lease
Finance lease right-of-use asset, net (included in property, plant and equipment, net)		30,265
Current portion of finance lease obligations		15,961
Finance lease obligations, net of current portion		27,231

As of March 31, 2019, weighted-average remaining lease term of operating leases and finance leases was 4.83 years and 3.49 years, respectively. The weighted-average discount rate for operating leases and finance leases was 9.80% and 7.85%, respectively.

The interest on financing lease liabilities for the three months ended March 31, 2019 was $0.8 million. The amortization expense on finance lease right-of-use assets for the three months ended March 31, 2019 was $3.4 million.

The following table summarizes maturities of finance and operating lease liabilities based on lease term as of March 31, 2019:



	Finance		Operating
	Leases		Leases
Remainder of 2019	$	15,199	$	20,636
2020		12,876		25,099
2021		10,119		20,194
2022		4,529		15,763
2023		3,062		11,671
2024 and thereafter		4,064		21,253
Total lease payments		49,849		114,616
Less: Imputed interest		6,657		8,958
Present value of lease liabilities	$	43,192	$	105,658

At December 31, 2018, the Company had the following future minimum payments due under non‐cancelable leases:


		Finance	Operating
		Leases	Leases
2019	$	20,080	$	38,057
2020		11,851		29,346
2021		9,018		22,239
2022		4,169		16,782
2023		2,244		12,302
2024 and thereafter		3,617		18,874
Total minimum lease payments	$	50,979	$	137,600
Less: imputed interest		6,743
Total net minimum lease payments		44,236
Less: Current portion of obligations under finance leases		17,498
Long-term portion of obligations under finance leases	$	26,738

Consolidated rental expense for all operating leases was $83.8 million for the year ended December 31, 2018. Consolidated rental expense for all operating leases was $15.1 million for the three months ended March 31, 2019.

The following table summarizes the cash paid and related right-of-use operating finance or operating lease recognized for the three months ended March 31, 2019.



		Three Months Ended
		March 31, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from finance leases		-
Operating cash flows from operating leases		9,374
Financing cash flows from finance leases		5,077
Right-of-use lease assets obtained in the exchange for lease liabilities:
Operating leases		2,904
Finance leases		4,097