Debt - Additional Information (Detail) (Senior Unsecured Credit Facilities, USD $)					0 Months Ended
	Dec. 31, 2013	Oct. 12, 2012	Dec. 31, 2013 Maximum	Dec. 31, 2013 Minimum	Oct. 12, 2012 KeyBank National Association	Dec. 31, 2013 Acquisition Covenants Maximum	Dec. 31, 2013 Acquisition Covenants Minimum
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 200,000,000
Debt instrument borrowing period					5 years
Credit Agreement accordion feature, incremental revolver or term loan amount		50,000,000
Leverage Ratio			3.50			3.5
Interest Coverage Ratio				3.0			3.0
Remaining borrowing capacity	57,105,000
Borrowings outstanding	0
Amount of outstanding letter of credit	$ 4,299,000