Writedowns and Other Charges - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Writedown Of Asset And Lease Loss Accrual [Line Items]
Writedown of capitalized debt costs	$ 9,552,000	$ 13,209,000	$ 0
Net lease loss accrual	8,625,000	14,748,000	0
Leasehold Improvements [Member]
Writedown Of Asset And Lease Loss Accrual [Line Items]
Writedown of assets		7,700,000
Excess Real Estate Capacity [Member]
Writedown Of Asset And Lease Loss Accrual [Line Items]
Net lease loss accrual	8,600,000	7,100,000
Secured Debt [Member]
Writedown Of Asset And Lease Loss Accrual [Line Items]
Early principal payments	235,000,000	300,000,000
Writedown of capitalized debt costs	$ 9,600,000	$ 13,200,000