Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2019

Compensation Related Costs [Abstract]

Schedule of Net Periodic Benefit Cost

The following table details the components of the net periodic (benefit) expense for black lung obligations:

	Three Months Ended September 30,					Nine Months Ended September 30,
	2019			2018		2019			2018
Service cost	$	751		$	194	$	1,558		$	582
Interest cost	1,567			174		3,386			521
Expected return on plan assets	(17		)	—		(49		)	—
Amortization of net actuarial loss	72			50		162			150
Net periodic expense	$	2,373		$	418	$	5,057		$	1,253

The following table details the components of the net periodic (benefit) expense for life insurance benefit obligations:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2019			2018			2019			2018
Interest cost	$	106		$	97		$	318		$	291
Amortization of net actuarial gain	(26		)	(11		)	(78		)	(33		)
Net periodic expense	$	80		$	86		$	240		$	258

The following table details the components of the net periodic (benefit) expense for pension obligations:

	Three Months Ended September 30,			Nine Months Ended September 30,
	2019			2019
Interest cost	$	6,636		$	19,929
Expected return on plan assets	(7,011		)	(21,032		)
Amortization of net actuarial loss	199			597
Net periodic benefit	$	(176	)	$	(506	)