Employer Sponsored Benefit Plans - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		0 Months Ended	1 Months Ended	3 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014 Pension Plan, Defined Benefit [Member]	Jul. 31, 2014 Pension Plan, Defined Benefit [Member]	Sep. 30, 2014 Pension Plan, Defined Benefit [Member]	Jul. 01, 2014 Pension Plan, Defined Benefit [Member]	Dec. 31, 2013 Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of eligible participants electing lump sum payment					62.00%
Pension lump sum payment						$ 10,300,000
Pension settlement charge	4,870,000	0	4,870,000	0			4,900,000
Tax benefit of non-cash settlement charge loss							1,900,000
Net pension plan liability								12,200,000	12,700,000
Expected domestic pension plan contribution in current year			4,200,000
Contributions made for domestic pension plan	$ 400,000	$ 300,000	$ 3,800,000	$ 900,000