Employer Sponsored Benefit Plan (Trust's Assets at Fair Value) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	$ 40,680	$ 36,355	$ 32,643
Us Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	10,548	10,835
Us Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	4,593	4,256
Non Us Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	9,465	6,187
Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	2,713	2,201
Us Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	10,461	9,487
Non Us Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	1,847	1,645
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	155	184
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	898	1,560
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	40,680	36,355
Fair Value, Inputs, Level 1 [Member] | Us Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	10,548	10,835
Fair Value, Inputs, Level 1 [Member] | Us Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	4,593	4,256
Fair Value, Inputs, Level 1 [Member] | Non Us Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	9,465	6,187
Fair Value, Inputs, Level 1 [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	2,713	2,201
Fair Value, Inputs, Level 1 [Member] | Us Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	10,461	9,487
Fair Value, Inputs, Level 1 [Member] | Non Us Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	1,847	1,645
Fair Value, Inputs, Level 1 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	155	184
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	898	1,560
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Us Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Us Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Non Us Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Us Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Non Us Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Us Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Us Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Non Us Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Us Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Non Us Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	$ 0	$ 0