Investments in Unconsolidated Investees (Combined Operating Results) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Schedule of financial data of unconsolidated investees, Combined Operating Results
Earnings from unconsolidated investee	$ 1,219	$ 1,347	$ 3,459	$ 4,489
Alliance-HNI, LLC and Subsidiaries
Schedule of financial data of unconsolidated investees, Combined Operating Results
Revenues	4,248	4,344	12,579	13,424
Expenses	2,528	2,306	7,349	6,624
Net income	1,720	2,038	5,230	6,800
Earnings from unconsolidated investee	860	1,023	2,615	3,595
Unconsolidated Investees, Including Alliance-HNI, LLC and Subsidiaries and Austin Cyberknife
Schedule of financial data of unconsolidated investees, Combined Operating Results
Revenues	7,354	7,228	20,550	21,239
Expenses	3,424	3,194	10,169	9,388
Net income	3,930	4,034	10,381	11,851
Earnings from unconsolidated investee	$ 1,219	$ 1,347	$ 3,459	$ 4,489