Commitments and Contingencies (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2014	Jun. 30, 2015
Loss Contingencies [Line Items]
Letters of credit outstanding amount			$ 17,211
Buckley Scott
Loss Contingencies [Line Items]
Period of contingent earnout provision		2 years
Maximum contingent consideration liability			2,017
Other noncurrent liabilities | Measured on a recurring basis
Loss Contingencies [Line Items]
Contingent earnout liability	[1]		1,170
Level 3 | Other noncurrent liabilities | Measured on a recurring basis
Loss Contingencies [Line Items]
Contingent earnout liability	[1]	$ 1,153	$ 1,170

[1] The fair value of the contingent earnout liability for the 2014 acquisition of Buckley Scott Holdings Limited ("Buckley Scott") was estimated using an internally-prepared probability-weighted discounted cash flow analysis. The fair value analysis relied upon both Level 2 data (publicly observable data such as market interest rates and capital structures of peer companies) and Level 3 data (internal data such as the Company's operating projections). As such, the liability is a Level 3 fair value measurement. The valuation is sensitive to Level 3 data, with a maximum possible earnout of $2,017,000. As such, the fair value is not expected to vary materially from the balance recorded. The fair value of the contingent earnout liability is included in "Other noncurrent liabilities" on the Company's unaudited Condensed Consolidated Balance Sheets, based upon the term of the contingent earnout agreement. The fair value of the earnout was $1,153,000 at December 31, 2014. The change in the Level 3 fair value at June 30, 2015 was due to foreign currency translation adjustments and inputed interest.