Capital Stock (Dividends Declared) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended										12 Months Ended			30 Months Ended
		Mar. 31, 2016		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015		Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2016
Equity [Abstract]
Dividends declared per common share (in usd per share)		$ 0.09	[1]	$ 0.09	$ 0.09	$ 0.07	$ 0.07	[1]	$ 0.07	$ 0.07	$ 0.05	$ 0.34	$ 0.26	$ 0.10	$ 0.70
Total amount	[2]	$ 13,209	[1]	$ 13,520	$ 13,364	$ 10,376	$ 10,186	[1]	$ 9,817	$ 9,590	$ 6,880	$ 50,469	$ 36,473	$ 13,966	$ 100,908
Cash dividends payable		$ 13,209					$ 10,186					$ 13,209	$ 10,186	$ 7,066	$ 13,209

[1] As of March 31, 2016 and March 31, 2015, the Company had $13.2 million and $10.2 million, respectively, of cash dividends payable included in accounts payable and accrued liabilities on the consolidated balance sheet.

[2] The Company had an accumulated deficit through December 31, 2014 at the time the dividends were declared; therefore, these dividends were recorded as a reduction to common shares with the dividends declared in the fourth quarter ended March 31, 2015 recorded as a reduction of retained earnings.