Employee Benefit Plan - Narrative (Details) - USD ($)	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Retirement Benefits [Abstract]
Amortization of amounts previously recognized in accumulated other comprehensive income	$ 321,000	$ 318,000
Contribution to pension plan	$ 0	$ 0

Amount after tax and reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration