Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Unamortized intangible assets (goodwill) [Roll Forward]
Gross balance at beginning of year	$ 3,905	$ 0	$ 0
Accumulated impairment balance beginning of year	0	0	0
Effect of Granite merger	300	3,905	0
Impairment	0	0	0
Accumulated balance at end of year	$ 4,205	$ 3,905	$ 0