Shareholders' Equity - Prospectus Supplement (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Nov. 10, 2014	May. 08, 2013
Prospectus Supplement July 18, 2014
Class of Stock [Line Items]
Maximum common stock value authorized under prospectus supplement				$ 100,000,000
Common Stock sold under prospectus supplement, in shares	0	0
Prospectus Supplement November 10, 2014
Class of Stock [Line Items]
Maximum common stock value authorized under prospectus supplement			$ 150,000,000
Common Stock sold under prospectus supplement, in shares	0	0