	December 31,
	2019		2018
Intangible assets:
Below market lease value, less accumulated amortization of $8,850		—		32,738
Deferred leasing assets, less accumulated amortization of $5,647 and $2,021, respectively		41,129		43,856
Other intangible assets, less accumulated amortization of $8,182 and $5,118, respectively		14,517		17,311
Construction receivable - Kansas lease		137,665		—
ROU lease assets		108,118		—
Lease incentive assets		5,454		6,096
Debt issuance costs, less accumulated amortization of $1,475 and $631, respectively		2,628		3,322
Cash equivalents and cash surrender value of life insurance held in Rabbi trust		14,448		13,977
Straight-line rent receivable		7,836		10,729
Insurance receivable		13,179		6,599
Other		5,933		6,579
	$	350,907	$	141,207

The gross carrying amount of intangible assets amounted to $69.5 million and $109.9 million at December 31, 2019 and 2018, respectively. Amortization expense related to intangible assets was $6.8 million, $6.5 million, and $3.4 million for 2019, 2018, and 2017, respectively, and depending upon the nature of the asset, was either reported as operating expense or depreciation and amortization in the accompanying statement of operations for the respective periods.

As of December 31, 2019, the estimated amortization expense related to intangible assets for each of the next five years is as follows (in thousands):