Lease Commitments - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Leases [Abstract]
Total rental expense including long term leases and all other rentals	$ 41,397	$ 39,290	$ 40,934
Amount for non-cancelable operating leases	$ 86,937