Acquisitions Business Combination Pro Forma (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Business Combinations [Abstract]
Revenues	$ 74,576	$ 62,470	$ 222,069	$ 174,653
Net income (loss) attributable to common stockholders	$ (3,085)	$ (4)	$ (21,518)	$ 2,527
Basic net income (loss) attributable to common stockholders	$ (0.04)	$ (0.01)	$ (0.34)	$ 0.09
Diluted net income (loss) attributable to common stockholders	$ (0.04)	$ (0.01)	$ (0.34)	$ 0.09