Condensed Consolidated Statements of Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common shares	Additional paid-in capital	Retained earnings	Shareholders' equity attributable to shareholders	Non-controlling interests
Balance, beginning of period at Dec. 31, 2012		$ 7,843	$ 762,430	$ 98,271		$ 59,777
Balance, beginning of period (in shares) at Dec. 31, 2012		78,432,132
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares (in shares)		0
Issuance of common shares		0	0
Share compensation expense			1,752
Net income	74,430			74,430
Income attributable to non-controlling interests	75,513					1,083
Contributions						201
Distributions						(35,129)
Balance, end of period at Mar. 31, 2013	970,658	7,843	764,182	172,701	944,726	25,932
Balance, end of period (in shares) at Mar. 31, 2013		78,432,132
Balance, beginning of period at Dec. 31, 2013	1,510,396	10,389	1,055,690	325,582		118,735
Balance, beginning of period (in shares) at Dec. 31, 2013		103,888,916
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares (in shares)		35,981
Issuance of common shares		3	(3)
Share compensation expense			2,252
Net income	39,779			39,779
Income attributable to non-controlling interests	40,795					1,016
Contributions						2,129
Distributions						(51,001)
Balance, end of period at Mar. 31, 2014	$ 1,504,571	$ 10,392	$ 1,057,939	$ 365,361	$ 1,433,692	$ 70,879
Balance, end of period (in shares) at Mar. 31, 2014		103,924,897