Employer Sponsored Benefit Plans - Plan Assets and Benefit Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in benefit obligation:
Service Cost	$ 46	$ 0	$ 0
Interest cost	2,595	2,058	2,139
Change in plan assets:
Fair value of plan assets at beginning of year	44,174
Fair value of plan assets at end of year	87,452	44,174
Balance sheet amounts:
Noncurrent liabilities	(22,795)	(9,743)
United States
Change in benefit obligation:
Net benefit obligation at beginning of year	51,882	50,086
Benefit obligation assumed through acquisition	52,392	0
Service Cost	46	0
Interest cost	2,595	2,058
Actuarial (gain)/loss	(876)	2,126
Gross benefits paid	(3,360)	(2,388)
Net benefit obligation at end of year	102,679	51,882	50,086
Change in plan assets:
Fair value of plan assets at beginning of year	44,174	37,038
Fair value of plan assets through acquisition	43,230	0
Actual (loss)/return on plan assets	(4,092)	5,924
Contributions	7,500	3,600
Gross benefits paid	(3,360)	(2,388)
Fair value of plan assets at end of year	87,452	44,174	$ 37,038
Net benefit obligation in excess of plan assets	(15,227)	(7,708)
Balance sheet amounts:
Current liabilities	(3,078)	0
Noncurrent liabilities	(12,149)	(7,708)
Total liabilities	(15,227)	(7,708)
Amounts recognized in accumulated other comprehensive income, net of tax consist of:
Net actuarial loss	21,850	17,632
Net amount recognized	$ 21,850	$ 17,632