Debt - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended			0 Months Ended	9 Months Ended	12 Months Ended
	Sep. 10, 2012	Dec. 31, 2013	Dec. 31, 2012	Sep. 10, 2012 Letter of Credit [Member]	Sep. 10, 2012 Revolving Credit Facility [Member]	Sep. 30, 2013 Revolving Credit Facility [Member]	Dec. 31, 2013 Revolving Credit Facility [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] Maximum [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] Minimum [Member]
Line of Credit Facility [Line Items]
Term for credit facility	5 years
Borrowing capacity					$ 75,000,000
Credit facility amount increase provision on condition					50,000,000
Repayment of debt		15,000,000				15,000,000
Limit for the issuance of standby letters of credit				7,500,000
Outstanding under the Credit Facility		$ 0	$ 15,000,000
Credit Facility Interest Periods							1, 2, 3 or 6 months
percentage of margin on principal amount								2.50%	0.75%
Commitment fee								0.50%	0.35%
Minimum interest coverage ratio							At least 4.00:1
Minimum percentage of interest adjustment							4.00
Leverage ratio							No greater than 2.75:1
Maximum indebtedness to EBITDA							2.75