Goodwill and Other Intangible Assets - Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Intangible asset amortization expense, excluding impairment charge	$ 1,300	$ 1,700	$ 3,000	$ 3,100
Estimated intangible asset amortization expense 2015	1,681		1,681
Estimated intangible asset amortization expense 2016	2,496		2,496
Estimated intangible asset amortization expense 2017	1,510		1,510
Estimated intangible asset amortization expense 2018	879		879
Estimated intangible asset amortization expense 2019	609		609
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	852		852
Finite-Lived Intangible Assets, Net	$ 8,027		$ 8,027		$ 20,690