Other Liabilities - Accrued and other liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Accrued and other liabilities	$ 7,822	$ 6,103
Tax-related [Member]
Accrued and other liabilities	1,136	1,197
Accrued Compensation And Related Taxes [Member]
Accrued and other liabilities	3,103	3,424
Deferred revenue [Member]
Accrued and other liabilities	675	299
Insurance [Member]
Accrued and other liabilities	521	0
Professional services [Member]
Accrued and other liabilities	248	282
Accrued fuel and rig-related charges [Member]
Accrued and other liabilities	291	162
Interest [Member]
Accrued and other liabilities	476	25
Other [Member]
Accrued and other liabilities	$ 1,372	$ 714