Discontinued Operations - Changes in Future Remaining Lease Obligations Discontinued Operations (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Discontinued Operations And Disposal Groups [Abstract]
Balance, Beginning of Period		$ 14,474	$ 21,751
Charges Incurred	[1]	365	(342)
Net Cash Payments		(2,719)	(3,740)
Balance, End of Period		$ 12,120	$ 17,669

[1] Includes subsequent adjustments for accretion, revised estimates and variances between estimated and actual charges, net of any reversals for terminated lease obligations.