Goodwill and Other Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Gross carrying amount at beginning of year	$ 22,114	$ 16,401
Additions	0	5,713
Accumulated amortization	(17,204)	(15,589)
Gross carrying amount at end of year	$ 4,910	$ 6,525