Summary of Significant Accounting Policies - Schedule of Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Amortization of employee benefit plan items:
Amounts reclassified from accumulated other comprehensive loss, tax	$ 16	$ (5,100)
Amount reclassified out of accumulated other comprehensive income (loss)	(97)	13,657
Plan settlement
Amortization of employee benefit plan items:
Total before tax	526
Amount reclassified out of accumulated other comprehensive loss
Amortization of employee benefit plan items:
Total before tax	(113)	18,784
Amounts reclassified from accumulated other comprehensive loss, tax	16	(5,127)
Amount reclassified out of accumulated other comprehensive income (loss)	(97)	13,657
Prior service cost
Amortization of employee benefit plan items:
Total before tax		(13)
Settlement expense
Amortization of employee benefit plan items:
Total before tax		19,900
Actuarial loss
Amortization of employee benefit plan items:
Total before tax	$ (639)	$ (1,103)