Fair Value Measurements - Summary of Change in Fair Value of Lease Exit Costs as Determined by Level 3 Inputs (Detail) (Level 3 [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 1,207
Adjustments	454
Payments	(172)
Change in fair value	11
Ending balance	$ 1,500