Deferred Sales Commissions, Net (Tables)

12 Months Ended

Dec. 31, 2018

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Components of Deferred Sales Commissions

The components of deferred sales commissions, net for the years ended December 31, 2018 and 2017 were as follows (excluding amounts related to fully amortized deferred sales commissions):

	December 31,
	2018			2017
	(in thousands)
Carrying amount of deferred sales commissions	$	926,188		$	911,852
Less: Accumulated amortization	(618,910		)	(597,566		)
Cumulative CDSC received	(290,130		)	(284,160		)
Deferred sales commissions, net	$	17,148		$	30,126

Expected Amortization of Deferred Sales Commissions

Estimated future amortization expense related to the December 31, 2018 net asset balance, assuming no additional CDSC is received in future periods, is as follows (in thousands):

2019	$	9,675
2020	4,561
2021	2,608
2022	237
2023	51
2024	16
	$	17,148