Retirement Plans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Net settlement loss		$ (1,900,000)	$ (2,000,000)
Minimum time period for expected rate of return	10 years
Maximum time period for expected rate of return	20 years
Accrued cost related to retirement plans included in other long term liabilities	35,100,000	19,900,000
Change in equity as a result of change in deferred net loss	(16,100,000)	14,700,000	1,900,000
Change in equity as result of change in deferred net loss taxes	2,600,000	7,100,000	1,100,000
Company contribution under deferred compensation plan	100,000	200,000	700,000
Retirement Savings Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Percentage of amount contributed by Company with respect to employee's contribution	100.00%
Discretionary profit sharing contribution	2.00%
Company contribution	300,000	500,000	4,700,000
Retirement Savings Plan [Member] | Maximum [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Maximum percentage of Company contribution of employee's salary	4.00%
REIT Conversion [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Net settlement loss		(700,000)
Corporate Operating Expenses [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Net settlement loss		(1,200,000)
Pension Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Rate of qualified earnings credited to the account of the participant of benefit plan	3.00%
Retirement age benefit payable to a terminated vested participant upon retirement	65
Retirement age for benefit payments, earliest age allowed contingent of minimum service requirement	55
Number of years of service at the time plan was frozen for the eligibility of benefit payable to terminated vested participant at age 55	15 years
Net settlement loss		(1,878,000)	(1,960,000)
Expected contribution to defined benefit plan	0
Net gain recognized in other comprehensive income	(18,700,000)	21,800,000
Unrecognized actuarial losses included in other comprehensive loss, net of tax	31,800,000	15,800,000
Unrecognized actuarial losses included in other comprehensive loss	(44,400,000)	(25,800,000)
Defined benefit plan amounts that will be amortized from accumulated other comprehensive income loss in next fiscal year	1,200,000
Non Qualified Retirement Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Accumulated benefit obligation for defined benefit plan	$ 16,200,000