Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Amortization of intangible assets	$ 10,888	$ 12,481	$ 17,184
Minimum
Finite-lived intangible asset, useful life	4 years
Maximum
Finite-lived intangible asset, useful life	10 years
Weighted Average
Finite-lived intangible asset, useful life	9 years 1 month 6 days
Weighted Average | Customer Relationships
Finite-lived intangible asset, useful life	9 years 1 month 6 days
Weighted Average | Technology-Based Intangible Assets
Finite-lived intangible asset, useful life	5 years 6 months