Pension Plans (Tables)

6 Months Ended

Jun. 30, 2019

Retirement Benefits [Abstract]

Components of net periodic pension cost

The components of net periodic pension cost for these defined benefit pension plans are as follows:

	For the Three Months Ended June 30,						For the Six Months Ended June 30,
	2019			2018			2019			2018
	(In thousands)
Service cost	$	7,789		$	8,299		$	15,766		$	16,715
Interest cost	1,305			1,226			2,629			2,469
Expected return on plan assets	(1,595		)	(1,417		)	(3,213		)	(2,859		)
Recognized actuarial gain	(94		)	(42		)	(188		)	(77		)
Net periodic pension cost	$	7,405		$	8,066		$	14,994		$	16,248

Summary of defined contribution expense

The following table summarizes our defined contribution expense:

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2019		2018		2019		2018
	(In thousands)
Defined contribution expense	$	3,352	$	3,017	$	7,756	$	7,013