Discontinued Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income (loss) from discontinued operations, net of income taxes	$ 3,392	$ (264)	$ (441)	$ 252	$ (8,893)	$ (660)	$ (541)	$ 546	$ 2,939	$ (9,548)	$ 1,831
Discontinued Operations [Member]
External revenue									13,518	14,264	11,921
Gain on disposal of long-lived assets, net									3,090	(9,196)	1
Income (loss) from discontinued operations before income taxes									2,935	(9,652)	2,162
Income tax expense									(4)	(104)	331
Income (loss) from discontinued operations, net of income taxes									$ 2,939	$ (9,548)	$ 1,831