Revolving Line of Credit - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 31, 2007
Line of Credit Facility [Line Items]
Borrowing capacity under revolving line of credit	$ 150			$ 30
Further increases in total commitment			175
Amount outstanding on line of credit	80.2	72.6
Available on revolving line of credit	69.8
Maturity date of the facility	Dec. 31, 2016
Qualified lease receivables eligible under the borrowing base computation	133.1
London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Amount outstanding on line of credit	70.0
Base Rate [Member]
Line of Credit Facility [Line Items]
Amount outstanding on line of credit	10.2
Minimum [Member]
Line of Credit Facility [Line Items]
Borrowing capacity under revolving line of credit			100
Interest rate on loans	2.65%
Maximum [Member]
Line of Credit Facility [Line Items]
Borrowing capacity under revolving line of credit			$ 150
Interest rate on loans	4.00%