Acquisitions Acquisitions (Pro Forma) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Business Acquisition [Line Items]
Revenue of acquiree since acquisition date, actual	$ 61,700,000	$ 7,700,000	$ 82,000,000	$ 7,700,000
Earnings or loss of acquiree since acquisition date, actual	3,100,000	800,000	5,100,000	800,000
2013 [Member]
Business Acquisition [Line Items]
Pro Forma Revenue		375,038,000		722,111,000
Pro Forma Net income (Loss)		13,885,000		24,724,000
2014 [Member]
Business Acquisition [Line Items]
Pro Forma Revenue		384,602,000	876,292,000	729,239,000
Pro Forma Net income (Loss)		$ 15,183,000	$ 25,817,000	$ 26,688,000