Goodwill and Intangible Assets - Future Amortization Expense of Finite-lived Intangible Assets (Details) (West Construction, Inc., USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2014	$ 55
2015	$ 87
Minimum
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Acquired intangible assets useful life	1 year
Maximum
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Acquired intangible assets useful life	3 years