Finite-Lived Intangible Assets and Liabilities and Goodwill
 6 Months Ended
Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]  
Finite-Lived Intangible Assets and Liabilities and Goodwill
7.    Finite-Lived Intangible Assets and Liabilities and Goodwill
Finite-Lived Intangible Assets and Liabilities
The following presents the major components of the finite-lived intangible assets and liabilities (in thousands):
 
 
June 30, 2018
 
 
Weighted Average Remaining Life
 
Gross
 
Accumulated Amortization
 
Net
Intangible assets
 
 
 
 
 
 
 
 
Power purchase agreements
 
16
 
$
224,528

 
$
(23,161
)
 
$
201,367

Industrial revenue bond tax savings
 
24
 
12,778

 
(611
)
 
12,167

Other intangible assets
 
33
 
13,898

 
(1,075
)
 
12,823

Leasehold interest
 
8
 
$
67

 
$
(2
)
 
$
65

Total intangible assets
 
 
 
$
251,271

 
$
(24,849
)
 
$
226,422

Intangible liabilities
 
 
 
 
 
 
 
 
Power purchase agreement
 
14
 
$
60,300

 
$
(10,840
)
 
$
49,460

Leasehold interest
 
23
 
8,858

 
(123
)
 
8,735

Total intangible liabilities
 
 
 
$
69,158

 
$
(10,963
)
 
$
58,195


 
 
December 31, 2017
 
 
Weighted Average Remaining Life
 
Gross
 
Accumulated Amortization
 
Net
Intangible assets
 
 
 
 
 
 
 
 
Power purchase agreement
 
15
 
$
127,084

 
$
(17,611
)
 
$
109,473

Industrial revenue bond tax savings
 
24
 
12,778

 
(351
)
 
12,427

Other intangible assets
 
34
 
15,234

 
(1,086
)
 
14,148

Total intangible assets
 
 
 
$
155,096

 
$
(19,048
)
 
$
136,048

Intangible liability
 
 
 
 
 
 
 
 
Power purchase agreement
 
15
 
$
60,300

 
$
(9,106
)
 
$
51,194


The Company presents amortization of the PPA assets and PPA liabilities as an offset to electricity sales in the consolidated statements of operations, which resulted in net expense of $2.5 million and $3.9 million for the three and six months ended June 30, 2018, respectively, and net expense of $0.7 million and $1.5 million for the same periods in 2017, respectively. For other intangible assets, the Company includes the amortization in depreciation, amortization and accretion in the consolidated statements of operations and recorded amortization expense of $0.1 million and $0.2 million for the three and six months ended June 30, 2018, respectively, and amortization expense of $0.1 million and $0.2 million for the same periods in 2017, respectively.
As part of the 2017 Broadview acquisition, the Company acquired an intangible asset related to future property tax savings resulting from the issuance of industrial revenue bonds during construction of the project. The intangible asset is being amortized to depreciation, amortization and accretion in the consolidated statements of operations. The Company recorded amortization expense of $0.1 million and $0.3 million for the three and six months ended June 30, 2018, respectively, and $0.2 million and $0.2 million for the same periods in 2017, respectively, related to the industrial revenue bond tax savings intangible asset.
As a result of the Japan Acquisition, the Company recorded $103.2 million of intangible PPA assets resulting from market prices that are lower than the contractual prices. In addition, the Company recorded a $9.3 million intangible leasehold interest liability, as a result of higher market prices compared to the contractual prices, which is being amortized to depreciation, amortization and accretion in the consolidated statements of operations.
The following table presents estimated future amortization for the next five years related to the Company's finite-lived intangible assets and liabilities (in thousands):
Year ended December 31,
 
Power purchase agreements, net
 
Industrial revenue bond tax savings
 
Other intangible assets
 
Leasehold interests
2018 (remainder)
 
$
4,874

 
$
256

 
$
278

 
$
(189
)
2019
 
9,748

 
512

 
556

 
(379
)
2020
 
9,748

 
512

 
556

 
(379
)
2021
 
9,748

 
512

 
556

 
(379
)
2022
 
9,748

 
512

 
556

 
(379
)
Thereafter
 
108,092

 
9,862

 
10,278

 
(6,968
)

Goodwill
In connection with the Japan Acquisition the Company recognized goodwill of $60.3 million, which was allocated to the power projects reporting unit.
The following table presents a reconciliation of the beginning and ending carrying amounts of goodwill (in millions):
 
 
Total
Balances at December 31, 2017
 
$
—

Net additions during the period(1)
 
60.3

Balances at March 31, 2018
 
$
60.3

Foreign currency translation adjustment
 
(2.6
)
Balances at June 30, 2018
 
$
57.7

(1) 
The Company recorded goodwill on March 7, 2018 as a result of the Japan Acquisition.