Revenue Recognition - Additional Information (Details)	6 Months Ended
	Jun. 30, 2018
Minimum
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer, contract term	1 year
Customer relationship period	10 years
Length of customer life	30 months
Maximum
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer, contract term	7 years
Customer relationship period	20 years
Length of customer life	49 months