Summary of Significant Accounting Policies - Goodwill and Other Intangible Assets (Details 5)	12 Months Ended
	Dec. 31, 2017
Goodwill and Other Intangible Assets
Finite-Lived Intangible Assets, Remaining Amortization Period	10 years 6 months
Customer-Related Intangible Assets
Goodwill and Other Intangible Assets
Finite-Lived Intangible Assets, Remaining Amortization Period	10 years 6 months
Technology and other intangibles
Goodwill and Other Intangible Assets
Finite-Lived Intangible Assets, Remaining Amortization Period	8 years 4 months