Noncurrent Deferred Tax Assets Recorded in Accumulated Other Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss)
Balance at beginning of period, Pension and Postretirement Benefit Plans	$ 29,016	$ 69,641	$ 29,198	$ 70,881
Other comprehensive earnings, tax effect, Pension and Postretirement Benefit Plans	271	201	89	(1,039)
Balance at end of period, Pension and Postretirement Benefit Plans	29,287	69,842	29,287	69,842
Balance at beginning of period, Unamortized Value of Terminated Forward Starting Interest Rate Swap	2,155	2,600	2,269	2,707
Other comprehensive earnings, tax effect, Unamortized Value of Terminated Forward Starting Interest Rate Swap	(116)	(108)	(230)	(215)
Balance at end of period, Unamortized Value of Terminated Forward Starting Interest Rate Swap	2,039	2,492	2,039	2,492
Balance at beginning of period, Net Non current Deferred Tax Assets	31,171	72,241	31,467	73,588
Other comprehensive earnings, tax effect, Net Non current Deferred Tax Assets	155	93	(141)	(1,254)
Balance at end of period, Net Non current Deferred Tax Assets	$ 31,326	$ 72,334	$ 31,326	$ 72,334