Retirement Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2018

Retirement Benefit Plans [Abstract]

Defined Contribution Plan Matching Obligations

Matching obligations, in connection with the plans which are funded in cash and typically contributed to the plans in March of the following year, are as follows (in thousands):

	U.S. Defined Contribution
Year ended December 31,
2018	$	8,928
2017		9,153
2016		8,625