Summary of Significant Accounting Policies - Additional information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Line Items]
Cash and cash equivalents description	90 days or less
Credit items after shipment and invoicing	30 days
Investment related borrowings	$ 0
Financial assets or liabilities at fair value	0	0
Threshold percentage	50.00%
Liability for unrecognized tax benefits	$ 0	$ 0
Anti-dilutive securities excluded from computation of earnings per share	0	0
Minimum [Member]
Accounting Policies [Line Items]
Open tax years for jurisdictions	2011
Income tax statutes expiration year	2015
Minimum [Member] | Leased Assets [Member]
Accounting Policies [Line Items]
Equipment leasehold improvements and leased assets useful life	7 years
Minimum [Member] | Equipment [Member]
Accounting Policies [Line Items]
Equipment leasehold improvements and leased assets useful life	3 years
Minimum [Member] | Leasehold Improvements [Member]
Accounting Policies [Line Items]
Equipment leasehold improvements and leased assets useful life	3 years
Maximum [Member]
Accounting Policies [Line Items]
Open tax years for jurisdictions	2013
Income tax statutes expiration year	2017
Maximum [Member] | Leased Assets [Member]
Accounting Policies [Line Items]
Equipment leasehold improvements and leased assets useful life	10 years
Maximum [Member] | Equipment [Member]
Accounting Policies [Line Items]
Equipment leasehold improvements and leased assets useful life	20 years
Maximum [Member] | Leasehold Improvements [Member]
Accounting Policies [Line Items]
Equipment leasehold improvements and leased assets useful life	13 years