Derivative Financial Instruments and Fair Value Measurement - Summary of Derivatives Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Assets:
Cash equivalents	$ 23	$ 25
Assets	8,397	8,493
Liabilities:
Senior unsecured notes	530,000	516,250
Liabilities	561,797	557,551
Supplemental Executive Retirement Plan [Member]
Assets:
Investments	3,164	2,635
Deferred Compensation Plan [Member]
Assets:
Investments	4,566	4,674
Commodities contracts [Member]
Assets:
Derivative assets	644
Foreign Exchange Contracts [Member]
Assets:
Derivative assets		1,159
Liabilities:
Derivative liabilities	4,834	9,886
Interest rate swap contracts [Member]
Liabilities:
Derivative liabilities	26,963	31,415
Level 1 [Member]
Assets:
Cash equivalents	23	25
Assets	3,187	2,660
Liabilities:
Senior unsecured notes	530,000	516,250
Liabilities	530,000	516,250
Level 1 [Member] | Supplemental Executive Retirement Plan [Member]
Assets:
Investments	3,164	2,635
Level 1 [Member] | Deferred Compensation Plan [Member]
Assets:
Investments	0	0
Level 1 [Member] | Commodities contracts [Member]
Assets:
Derivative assets	0
Level 1 [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative assets		0
Liabilities:
Derivative liabilities	0	0
Level 1 [Member] | Interest rate swap contracts [Member]
Liabilities:
Derivative liabilities	0	0
Level 2 [Member]
Assets:
Cash equivalents	0	0
Assets	5,210	5,833
Liabilities:
Senior unsecured notes	0	0
Liabilities	31,797	41,301
Level 2 [Member] | Supplemental Executive Retirement Plan [Member]
Assets:
Investments	0	0
Level 2 [Member] | Deferred Compensation Plan [Member]
Assets:
Investments	4,566	4,674
Level 2 [Member] | Commodities contracts [Member]
Assets:
Derivative assets	644
Level 2 [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative assets		1,159
Liabilities:
Derivative liabilities	4,834	9,886
Level 2 [Member] | Interest rate swap contracts [Member]
Liabilities:
Derivative liabilities	26,963	31,415
Level 3 [Member]
Assets:
Cash equivalents	0	0
Assets	0	0
Liabilities:
Senior unsecured notes	0	0
Liabilities	0	0
Level 3 [Member] | Supplemental Executive Retirement Plan [Member]
Assets:
Investments	0	0
Level 3 [Member] | Deferred Compensation Plan [Member]
Assets:
Investments	0	0
Level 3 [Member] | Commodities contracts [Member]
Assets:
Derivative assets	0
Level 3 [Member] | Foreign Exchange Contracts [Member]
Assets:
Derivative assets		0
Liabilities:
Derivative liabilities	0	0
Level 3 [Member] | Interest rate swap contracts [Member]
Liabilities:
Derivative liabilities	$ 0	$ 0