Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Allowance for Doubtful Accounts
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 489		$ 566		$ 488
Additions Charged to Costs and Expenses	166		430		115
Additions Charged to Other Accounts	0		0		0
Deductions	403		507		37
Balance at End of Period	252		489		566
Valuation Allowance of Deferred Tax Assets
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	4,650	[1]	3,753	[1]	2,008	[1]
Additions Charged to Costs and Expenses	2,232		999	[1]	1,815	[1]
Additions Charged to Other Accounts	0		0	[1]	0	[1]
Deductions	0		102	[1]	70	[1]
Balance at End of Period	$ 6,882		$ 4,650	[1]	$ 3,753	[1]

[1] See Note 2 to our consolidated financial statements included in Part IV, Item 15(a) of this Annual Report on Form 10-K.