Noncurrent Deferred Tax Assets Recorded in Accumulated Other Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss)
Balance at beginning of period, Pension and Postretirement Benefit Plans	$ 29,287	$ 69,842	$ 29,198	$ 70,881
Other comprehensive earnings, tax effect, Pension and Postretirement Benefit Plans	(96)	(1,566)	(7)	(2,605)
Balance at end of period, Pension and Postretirement Benefit Plans	29,191	68,276	29,191	68,276
Balance at beginning of period, Unamortized Value of Terminated Forward Starting Interest Rate Swap	2,039	2,492	2,269	2,707
Other comprehensive earnings, tax effect, Unamortized Value of Terminated Forward Starting Interest Rate Swap	(120)	(111)	(350)	(326)
Balance at end of period, Unamortized Value of Terminated Forward Starting Interest Rate Swap	1,919	2,381	1,919	2,381
Balance at beginning of period, Net Non current Deferred Tax Assets	31,326	72,334	31,467	73,588
Other comprehensive earnings, tax effect, Net Non current Deferred Tax Assets	(216)	(1,677)	(357)	(2,931)
Balance at end of period, Net Non current Deferred Tax Assets	$ 31,110	$ 70,657	$ 31,110	$ 70,657