Goodwill and Other Intangible Assets - Identifiable Intangible Assets Subject To Amortization (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Total other intangibles, gross	$ 29,081	$ 29,081
Less accumulated amortization	15,279	14,672
Other intangibles, net	13,802	14,409
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Total other intangibles, gross	$ 29,081	$ 29,081