Goodwill and Other Intangible Assets Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Finite-lived Intangible Assets [Roll Forward]
Balance at the beginning of the year	$ 1,615	$ 1,086	$ 1,513
Additions as a result of acquisitions	11,194	1,072	0
Less: amortization expense	1,920	543	427
Balance at the end of the year	$ 10,889	$ 1,615	$ 1,086