Fair Value - Fair Value Measurements (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
West Construction, Inc. | Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets acquired in business combinations	$ 0
Goodwill and other intangibles	0
West Construction, Inc. | Nonrecurring | Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets acquired in business combinations	0
Goodwill and other intangibles	0
West Construction, Inc. | Nonrecurring | Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets acquired in business combinations	5,936,000
Goodwill and other intangibles	3,352,000
Fair value of earnout liability	(271,000)
West Construction, Inc. | Nonrecurring | Estimate of fair value, fair value disclosure
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets acquired in business combinations	5,936,000
Goodwill and other intangibles	3,352,000
Fair value of earnout liability	(271,000)
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Fair Value Disclosure	$ 8,600,000	$ 12,600,000